Dawson Casting

""This is just like The OC, except without 25-year old teenagers and 35-year old parents.""

- Jack, Will and Grace

High school students in television look nothing like high school students in real life (well, not always), for one good reason: they're played by actors who are upwards of ten-to-fifteen years older. This dates back to the earliest days of Hollywood, if not further, making it Older Than Television.

Despite this trope being a prime source for ridicule, mockery, and parody, there are actually a lot of legit reasons this is done.
 * 1) Labor laws and regulations are probably the biggest reason. They apply to acting just as they do any other profession. There are a whole string of laws that child actors are subject to, including; (in the UK and the USA) education requirements and night shoot and work hours restrictions. These aren't the ideal condition when trying to meet the deadlines for finishing a film or a TV season.
 * 2) The vast majority of professional actors are twenty and up anyway, so if you hold an audition for a teen role, nine out of ten of the actors you see will be an inappropriate age, and they'll be the ones with good CVs.
 * 3) The pressures of stardom are harder for a teen actor to handle than a young adult. An actor in his or her twenties is less likely to leave a show after one season (or film series after one entry) to focus on his or her education than an actual teenager is.
 * 4) It's easier to see the difference between a teen and a young adult if you are a teen or young adult. Casting directors are often middle-aged or older; to them a 16-year-old doesn't look noticeably younger than a 21-year-old.
 * 5) Puberty tends to be extremely fickle; a cute 14-year old can transform into a gawky, gangly 16-year old with rather shocking celerity. Or vice versa. Of course this won't happen if you've already been through puberty.
 * 6) Obscenity and child porn laws. In the US, it's generally illegal to do anything that even simulates sex on film unless everyone involved is 18 or older. Therefore, having older actors allows the filmmakers to depict various acts on camera that would get them thrown in jail if the actors were underage.
 * 7) Related to the above, this allows for Fan Service, which is legal as long as it's non-nude.
 * 8) Most successful teen actors -- i.e the ones with the most experience and impressive resumes -- tend to be physically smaller than other actors, and look younger than their actual age, because they are the child-analogues of Dawson Casting (due to more experience, more able to remember lines, less likely to go completely Off the Rails on some random whim, etc.), better-suited to playing younger children than real children would be.
 * 9) Stage parents can be a pain in the ass for filmmakers, butting in and trying to dictate various parts of the production.

This ought to be horribly distracting, but by and large, television audiences have learned to manage. It can sometimes result in a paradoxical effect: teens that look more like actual teens (either with real teenage actors or in animation) are described as looking "too young" (see Reality Is Unrealistic). Conversely, actors in their early-to-mid-twenties, especially those who make their name in these kinds of shows, often have difficulty being taken seriously playing characters their own age.

This happens far most often when dealing with teenage characters in the range of 14-18 years old, especially in dramatic shows. If younger, casting usually tries for children actors, and if older it is simply far less noticeable. If a show or movie carries a greater focus on the adults rather than the kids then they will usually avert this.

Very specific actors can pull it off, usually attributing it to the character being Older Than They Look. In other cases, some stories work with this because a key plot point may be the character does not actually look their age, or because the actor looks younger (for example many do not realize Sissy Spacek was not actually a teen in Carrie). But with no such luck Hollywood will get by with appropriate clothing, hairstyles, makeup and mannerisms.

Named for Dawsons Creek, which was notorious for it -- James Van Der Beek (20), Katie Holmes (18) and Joshua Jackson (19) playing 15-year olds (at the time of the pilot's filming). 17-year old Michelle Williams was the only one still high school aged.

The below ages are generally at the time the movie was released or the first episode aired; the actors are of course younger during filming. Simply put, a 20-year old does not physically look like a 14-year old.

Note that many works can end up on both the examples and exceptions due to either mixing casts or the aging of cast members over a series. Be sure to specify which performers fit the examples and which fit the exceptions.

And because voice acting has nothing to do with appearance and everything to do with vocal performance, only notable aversions should be mentioned in that regard (it would be like complaining they didn't get an actual alien to voice an alien). Likewise, this is intended primarily towards adults playing teenagers and not about simple age discrepancies. There's a good explanation for why this may be done for voice acting, too - having actual children to voice actual child characters is sometimes complicated because kids age, have their own lives ahead of them, enter puberty (and voices change) etc. This is also part of why we have Cross-Dressing Voices - see below.

This trope is less noticeable with females as it is with males as females tend to fully mature physically at an earlier age by 14 or 15. Where as Males tend to not full mature until their late teens. Which makes a Male actor in his 20's playing a 15 year old less believable than it is with a female of the same age playing a 15 year old.

Compare Age Lift, Age-Inappropriate Dress, Hollywood Old and Playing Hamlet. Contrast Playing Gertrude. See also Artistic Age for an intentional drawn equivalent. Cross-Dressing Voices is more-or-less the animated version of this trope, as partially explained above.

Fan Fiction

 * Although there's generally no actual casting involved, many fanfics involve describing the characters (both existing and new) in terms that don't fit with eleven to seventeen years old. Sometimes there actually is casting, when the author creates banners or pictures for the cast, and generally uses models or actresses in their young 20s.
 * A notable example would have to be The Girl Who Lived, which references pictures of well-endowed porn actresses in their late 20s as pictures of the main cast all the way back when they were 11.
 * Practically all Role Players cast their characters into age illogical celebrities.
 * In the author's notes of My Immortal, Tara Gilesbie suggested that Gerard Way (!) should play Draco in Leather Pants in the next Harry Potter film.

Film

 * Inverted in Click where 19 year old Katie Cassidy plays the 27 year old version of Adam Sander's daughter
 * Inverted in Crazy Stupid Love with 22 year old Emma Stone playing a character who is at least 25.
 * Eurotrip: Most of the actors playing 18 year olds were in there 20s even Kristin Kreuk was in her 20s playing a 17 year old.
 * The Roommate is pretty bad. Minka Kelly, born in 1980 and Leighton Meester, born in 1986, play college freshmen. Freshmen born during the setting of this film would have been born in 1992.
 * Teen idol Elvis Presley, in his 20s and beyond, would portray characters that were explicitly adolescent, such as in King Creole and Love Me Tender, or age-unspecified young adults who live with their parents, aren't yet married, headed for college or the military, are newcomers on the entertainment scene, hold down jobs suitable for high school dropouts, and enjoy youthful beach parties.
 * In the original 1958 version of The Blob, high-schooler Steve Andrews is played by 28-year old Steve McQueen in his first starring role.
 * Annette Funicello and Frankie Avalon. Both were born in the early 1940s, and both starred in a series of Beach Movies in the late 1960s with vague plots about how "school is out, so let's go to the beach."
 * Fabiano Anthony Forte often played a restless teenager with a penchant for singing.
 * Mr. Holland's Opus - Rowena, the high school senior who tempts Mr. Holland because she's intellectually mature and looks older than her years? She looks mature for her age because she was played by 23-year old Jean Louisa Kelly. The baby-faced 13-year old freshman clarinet player who later becomes governor? Played by 20-year old Alicia Witt.
 * All of the "kids" from Easy A are between 21 and 25 years old. This actually presents a minor problem, as one of the characters is supposed to be too old for high school, having been held back repeatedly, but appears indistinct from the other actors. Additionally, they had gotten age-appropriate actors for the flashbacks, and this meant that, in the four years between the past and present, the characters seemed to have aged ten years.
 * The Saturday Night Live movie Superstar had high school students who were mostly in their 20s. Leading roles go to Elaine Hendrix, 29, Will Ferrell, 32, and Molly Shannon, 35. Apparently, that was supposed to add to the humor.
 * Female Trouble - Mink Stole, in her late 20s, plays a 14-year old, and it's heavily lamp shaded.
 * In Dirty Dancing Frances is 17 years old; Jennifer Grey, who played her, was 27 but looked suitably young. Johnny is 25 years old, and played by 35 yr old Patrick Swayze, who unfortunately looked his age, making it look a bit squicky.
 * Howard Stern in his film Private Parts played an 18 year old version of himself... He was 42 at the time. The incongruity is extremely obvious when we first see him walking around campus, and Stern (as a Narrator) comments that "for this movie you've got to suspend disbelief."
 * Ralph Macchio was in his early twenties when he first played the 15-year old Daniel La Russo in The Karate Kid. By the time the third movie came out, Macchio was still playing teen-aged Daniel despite being in his late twenties. (His boyish good looks and the fact that his voice remained in a higher register after breaking helped.)
 * An (in)famous movie example: 33-year old Stockard Channing as 17-year old Rizzo in Grease (not to mention most of the rest of the "teenagers" in the cast; of the central teen characters, only one was actually a teenager -- then-19-year old Dinah Manoff).
 * In Rock 'n' Roll High School, all the "teen" actors are, at the youngest, in their mid twenties. The main character, Riff, was played by 29-year old P.J. Soles. The sequel Rock 'n' Roll High School Forever also features a teen cast of twenty somethings.
 * In the 1954 White Christmas, 32-year old Vera Ellen plays Judy Haynes; Judy's age is never expressly given, but based on comments made by other characters (she is repeatedly called "kid" and "little Judy"), that she orders a malted when the others order alcohol, and that 25-year old Rosemary Clooney plays her older sister Betty, it appears that she's supposed to be about 19.
 * In Peggy Sue Got Married 32-year old Kathleen Turner plays 40-year old Peggy Sue. So far, so good. Peggy Sue is then transported back to her senior year of high school, and Turner also plays the 18-year old version of Peggy Sue.
 * 16-year old Judy Garland was cast as the 11-year old Dorothy Gale in The Wizard of Oz (indeed, most people who haven't read the books don't realize Dorothy isn't supposed to be a teenager). Legend has it the studio forced her to wear a tight band around her breasts to make them less noticeable during the filming, among the many other nasty things they did to her and other actors of the day.
 * The movie version of The Wiz has 33-year old Diana Ross managed to get herself cast as Dorothy, pushing out 20-year old Stephanie Mills (who was the stage Dorothy) in the process.
 * Ellen Page is frequently cast as a teenager (14 years old in Hard Candy, 15 years old in  The Tracey Fragments, 16 years old in Juno, and 17 years old in Whip It), despite being 18 to 22 respectively at the time of their production. Ditto for her roles in An American Crime (where she played 16-year old Sylvia Likens) and X Men the Last Stand (where she played the teenage Kitty Pryde).
 * Porky's, probably the prototypical teen sex farce, featured an entire cast over 20 playing high school students, so that it could actually show nudity.
 * Cry Wolf features Lindy Booth (in her mid-20s at time) as an 18-year old.
 * Romeo and Juliet: Juliet is explicitly said to be 13, and Romeo is repeatedly called a "youth," so he's probably not much older. Mercutio is a good friend, so he's probably a comparable age to Romeo. Examples of noticeably older actors taking the roles:
 * Leslie Howard, at 43, played Romeo in a 1936 version and Juliet was played by 34-year old Norma Shearer). Even more geriatric was John Barrymore, Sr. as Mercutio, who was fifty-four at the time.
 * At the time of filming of the 1968 Franco Zeffirelli film, Olivia Hussey and Leonard Whiting were 15 and 17 respectively. This was considered a radical innovation at the time, and much of the film's success was due the stars' very believable youthful passion. Ironically Olivia Hussey wasn't allowed to attend the debut of the film because the film had nudity and she was too young. It was her own nudity that she was prevented from seeing.
 * In the 1996 movie, William Shakespeares Romeo and Juliet, Claire Danes (playing the 13-year old Juliet) was actually sixteen. They almost averted this trope, as Natalie Portman (aged 14) had been initially cast in the role. However, during rehearsals it was thought that she looked too young, and the part was recast.
 * Some of the stars of High School Musical are in their twenties. Most were at a reasonable age at the start, but the time of the films moves differently then real time. Monique Coleman obviously fits at age 26, though she doesn't look it.
 * In the 1974 Werner Herzog film Jeder für sich und Gott gegen alle (also known as The enigma of Kaspar Hauser), the lead role of about-16-year old Kaspar Hauser was played by 41-year old street musician Bruno S. Herzog has commented that he was chosen for the role because his life had parallels with that of the historical Kaspar Hauser, and also because he gave the impression of being outsider to society at large, one that was a stranger to his own body.
 * Harry Potter: Moaning Myrtle (a ghost who died in her teens) was played by then-37-year old Shirley Henderson in Chamber of Secrets (her being a ghost, her appearance thusly being quite worked-over already and somewhat obscured by the opticals involved, probably helped hide the fact).
 * A convoluted example involves Tom Riddle, who appears as a 16-year old in two films made seven years apart. In Chamber of Secrets, 23-year old Christian Coulson played Riddle. By the time Half-Blood Prince rolled around, Coulson was pushing 30 and the part was recast with actual 16-year old Frank Dillane.
 * Deathly Hallows Part 2 features an inversion, where
 * Michael J. Fox played the teen-aged Marty McFly of the Back to The Future films into his late twenties, having done the first film when he was twenty-three. The actors playing Marty's parents and Biff, appearing as teenagers in the 1955 scenes, had similar ages.
 * Parodied in Scary Movie. In a "If this were a movie" conversation, one character says "We'd be played by actors in their late 20s/early 30s". The characters then pause for a moment, letting the phrase sink in.
 * Also done in the similar spoof Shriek If You Know What I Did Last Friday the Thirteenth, although never addressed.
 * Pride and Prejudice:
 * The BBC adaptation from 1995 included Julia Sawalha (then in her late twenties) as 15-year old Lydia Bennet.
 * The 1940 adaptation plays this trope straight. 36-year olds Laurence Olivier and Greer Garson played 28-year old Mr. Darcy and 20-year old Lizzie respectively.
 * Jake Gyllenhaal was 23 when he was cast as a teenager in the 2004 movie The Day After Tomorrow.
 * Most of the actors in The Breakfast Club were out of high school, with only 2 actually being under 18.
 * Graham Phillips (age 14) plays the titular Ben 10 in the Made for TV Movie Ben 10 Race Against Time. His also-10-year old cousin Gwen was played by Haley Ramm, age 15. In the sequel, 15-year old Ben is portrayed by a 23-year old.
 * Kidulthood stars Noel Clarke, who was 29 when playing the 18-year old leading man Sam. At 32, Clarke returned to play a 24-year old Sam in the sequel Adulthood.
 * Clueless:
 * Stacey Dash was 28 portraying a 16-year old in the movie and then came back for the TV show where she played a 16-year old until she was 31. (Dee, Stacey's character, lampshaded this in one episode when she mentioned when they were 27 they'd be "old enough to play teenagers on TV.")
 * The rest of the teen cast had an average age of 21, but 19-year old Alicia Silverstone and 18-year old Brittany Murphy work fairly well as 16-year olds.
 * In The Film of the Book of The World According To Garp, Garp is played from age 15 and up by then-30-year old Robin Williams.
 * David Lynch loves this trope.
 * Twin Peaks, Fire Walk with Me takes place days before the TV show and all the 20-something actors (mentioned in the TV section) are a few years older, with some flashbacks taking place years before the TV show, and Sheryl Lee playing 15. There were some additions to the movie that weren't in the TV show, such as 24-year old Moira Kelly as 17-year old Donna Hayward, and 27-year old Pamela Gidley as 17-year old Teresa Banks.
 * In Wild at Heart, 23-year old Laura Dern plays her character as a 13-year old in flashbacks, and Laura Dern had trouble passing as a teen when she was one, for instance when she was 19 in Blue Velvet.
 * In Dune: Sting (then 33) and Kyle MacLachlan (then 25), play Paul Atreides and Feyd Harkonnen, notwithstanding that both those characters are between the ages of 15 and 18 for the entirety of the original novel. To be fair, the makers of the TV miniseries of Dune also went for this trope as well, citing the availability of credible 15-year old actors to play the lead part.
 * Mean Girls had 25-year old Rachel McAdams and 21-year old Lacey Chabert and Lizzy Caplan playing High School Juniors. On the other hand, Amanda Seyfried and Lindsay Lohan, both also playing 16-year olds, were 18 years old and 17 years old respectively. Amy Poehler, who played McAdams' character's mother, is only six years older than she is.
 * Carrie:
 * The eponymous character was a high school senior and portrayed by a 26-year old Sissy Spacek, the same as P.J. Soles, who played Norma Watson. As well as the other teenagers, who were, oddly enough, only a few years younger than the actor playing Miss Collins.
 * Angela Bettis was 29 when she portrayed Carrie in the remake.
 * Four years later, Spacek played Loretta Lynn in Coal Miner's Daughter -- starting at the age of 14.
 * Parodied in Walk Hard, where the 14-year old version of Dewey Cox is played by 42-year old John C. Reilly, and his 12-year old child bride Edith is played by 34-year old Kristen Wiig. The other students in the scene are a grab bag of realistic and hilariously inappropriate age. This scene was intentionally made even sillier by the fact that it is immediately preceded by 8-year old Dewey being played by actual 8-year old Conner Rayburn.
 * In Rian Johnson's Brick, Joseph Gordon-Levitt, Nora Zehetner, Emilie de Ravin, and Meagan Good were twenty-two years old during production, playing high school students, and Brian J. White was twenty-eight.
 * In Gregg Araki's Mysterious Skin, 23-year old Joseph Gordon-Levitt plays a teenager.
 * Tim Roth played a 19-year old serial killer in a TV movie ''Murder in the Heartland". He was 33 when it aired. Being short and thin probably helped but couldn't fully cover the age difference.
 * In City of Ember one of the two 12-year old leads is played by Saoirse Ronan, who was 13 at the time of filming. The other is played by Harry Treadaway, who turned 23 during production.
 * In the film version of Astrid Lindgren's The Brothers Lionheart 12-year old Jonatan was played by Staffan Götestam who was 26 at the time. However the character was aged up intentionally as it seemed a bit improbable on film that a 12-year old would be entrusted with such a degree of leadership in a La Résistance group.
 * The 1996 film version of The Birdcage features Ally McBeal star Calista Flockhart playing an 18-year old. She was 31 at the time of filming. Dan Futterman, who plays her (20-year old) fiance, was about 28.
 * The 1936 Yiddish musical Yidl Mitn Fidl (Yidl With His Fiddle) stars the Yiddish stage icon Molly Picon, who was about 37, as a teenage girl (who poses as a boy, then falls in love).
 * Parminder Nagra was 26 when she played 18-year old Jess in Bend It Like Beckham.
 * George Mather was 42 when he portrayed 22-year old college student Lewis B. Moffet in Ring of Terror. Most of the cast catches grief from Joel and the bots for looking too old for their roles.
 * Almost every live-action adaptation of Jane Eyre. Jane is supposed to be 19 when she starts working for Mr. Rochester, yet she has been played by: 28-year old Susannah York (1970 film), 23-year old Sorcha Cusack (1973 miniseries), 28-year old Zelah Clarke (1983 miniseries), 24-year old Charlotte Gainsbourg (1996 film) and 25-year old Ruth Wilson (2006 tv miniseries).
 * In the 1920 silent film Pollyanna, 27-year old Mary Pickford plays a 12-year old girl.
 * Pickford was famous during much of her career for playing child characters: cf. The Poor Little Rich Girl, Rebecca of Sunnybrook Farm, Through the Back Door, and Little Lord Fauntleroy (in which she played a 10-year old boy).
 * Famous for pulling it off, too. In Sparrows, she is 34, but she plays a young teenager. Her co-stars for most of the film are children ranging from about age six to age 10, so if she were obviously much older, it would show up in contrast to the real children, but it doesn't.
 * The best example has to be Hating Alison Ashley, which centers around a year 9 (though it was grade six in the book) camping trip. The actors in the movie version were 20 and 21 at the time of its release.
 * Yentl, with a 40-year old Barbra Streisand in the title role. In the original short story by I.B. Singer, Yentl seems to be younger than 20, although Streisand made the character 28 years old in the movie. Interesting in that the plot revolves around the main character disguising herself as a young man to study in a yeshiva, which when done by a 40-year old woman stretches the imagination a bit. Then again, so does Streisand's Brooklyn accent in a movie set in Poland around the turn of the century. (The Mad satire "Mentl" summed it up perfectly by having her disguise be seen through by a blind man!)
 * Mandy Patinkin was 30; his character Avigdor's age is never given, but he's young enough to be eagerly awaiting his wedding night.
 * In the 1962 film The Manchurian Candidate, Angela Lansbury plays the mother of Laurence Harvey's character, despite being only two years older than Harvey; both actors were in their mid-30s when the film was made.
 * The satirical 1966 film Lord Love a Duck has high-schoolers played by 23-year old Tuesday Weld and 38-year old Roddy McDowall.
 * In the first Spider-Man film, Tobey Maguire and James Franco were about 26 and 23, respectively, playing high school seniors.
 * Andrew Garfield, who portrays the character in the 2012 reboot film, is 27 playing what will be a high school student.
 * Willow inverts the trope by featuring then-17-year old Warwick Davis as a father of two who must be in his 30s at least.
 * Richard Wilson was 21 when he played Mikey in The Proposition, who is implied to be about 14.
 * Matthew Broderick gets mentioned further down in Theater, but Ferris Buellers Day Off merits notation. Matthew Broderick was 24 at the time, Jennifer Grey (Ferris' younger sister) was 26, but Alan Ruck (Cameron) topped them both by turning thirty a few weeks after the film was released.
 * Teenagers from Outer Space
 * Another really bad example comes from the rather poor film adaptation of the novel Flowers in the Attic by V. C. Andrews, in which actors that look like adults are cast as characters who, in the book, were 14 and 12. This even breaks the plot; the male lead is large enough to simply physically overpower his abusive grandmother while the rest of his siblings simply walk out the front door of the mostly empty mansion.
 * The Graduate paired 30-year old Dustin Hoffman as a recent college graduate, and 36-year old Anne Bancroft as the middle-aged wife of his father's business partner. Not to mention 27-yr old Katharine Ross as her daughter Elaine.
 * 37-year old Gene Hackman was originally cast as Bancroft's husband, but Mike Nichols decided he couldn't pull off the middle-aged look as well as she could and wound up recasting the role.
 * Played With in Matchstick Men, an older actress playing a young girl...
 * Alison Lohman also played a teenager girl in Flicka when she was 25.
 * Malcolm McDowell was 27 when he played Alex in A Clockwork Orange. In the original novel, Alex is 15 years old.
 * Most of the high school freshman class in Freedom Writers were played by actors ridiculously too old to be playing 14-year olds. The most prominently featured student was played by April L. Hernandez, who was fourteen in the time period the film is set. This makes her just six years younger than Hilary Swank, who played the teacher.
 * In the 2007 movie The Namesake, based on the book by Jhumpa Lahiri, Kal Penn is Gogol/Nikhil in high school(as well as throughout his life). Kal Penn is 32, and he is only 7 years younger than the actress playing his mother (Tabu). Also, Moushumi Mazumdar is played by Zuleikha Robinson when Moushumi is in high school and in her 30s, but Robinson seems to pull it off better.
 * Played with in Suspiria: For his horror classic, Dario Argento wanted to have the students of the girls' boarding school to be prepubescent to increase the emotional impact and play into the dark fairy tale theme. His producers nixed the idea because of the difficulties of hiring and working with so many child actors on such a project. Argento compensated by having all the students (played by actresses in their 20s) behave immaturely and building sets that made them look small.
 * The Girl in Gold Boots. Buz is supposed to be college age, but the actor is clearly in his early 40's.
 * Attack of the Eye Creatures. John Ashley was 30 when he played high school student Stan Kenyon.
 * Teenage Caveman. Robert Vaughn was only 26 when playing the titular character, but looked older due to the brylcreem (which somehow survived the apocalypse).
 * Many of the actors in Kids, including Chloe Sevigny, were 18 and older (but really did look and act like young teens).
 * The 1983 film version of SE Hinton's The Outsiders cast a then 31-year old Patrick Swayze to play the protagonist's 18-year old elder brother.
 * In The Aviator, Gwen Stefani plays Jean Harlow, who was 19 at the time the film shows her; Gwen was 34 during filming, five years older than Jean when she passed away.
 * In The Phantom Tollbooth 16-year old Butch Patrick played 12-year old Milo.
 * Richard Linklater's Dazed and Confused sometimes plays it straight: Christine Harnos and Sasha Jenson portrayed incoming high school seniors despite being older than age-appropriate Matthew McConaughey, who played a twenty-something graduate.
 * 19-year old Summer Bishil played a 13-year old in Towelhead. This is somewhat lampshaded by a line even featured in the trailer in when hearing her age a character responds "You look older." Somewhat justifiable in that there is no way such a young actress would ever be cast in a movie with its sexual content.
 * The Goonies: 26-year old Steve Antin plays the high school bully Troy.
 * Danielle Harris was 29 when she portrayed the 17-year old Annie Brackett in Rob Zombie's Halloween, the same as Nancy Kyes, who portrayed Annie in the original 1978 version. Kristina Klebe, who played Linda in the remake, was also 29. PJ Soles was also in her late 20s and had a habit of playing pig-tailed teens back in the 1970s. Jamie Lee Curtis was 20 playing a teen in the first Halloween, and 23 playing the same teen on the same night in Halloween II. Bob, the guy who gets was 33.
 * In Halloween 4, Rachel was played by 25 year old Ellie Cornell, her boyfriend Brady was played by 24-year old Sasha Jensen, and Brady's mistress Kelly was played by 23-year old Kathleen Kinmont. In Halloween 5, Rachel's friend Tina is played by 23-year old Wendy Kaplan, and the average age of Tina's other friends is 25.
 * 14-year old Jamie Lloyd is played by 20-year old J.C Brandy in part 6.
 * Jamie Lee Curtis was 22 when she did Prom Night. The "girl" who gets chased around forever is 23.
 * The first sequel is worse, especially the bald teen at the beginning. There's also an O.C type situation with Vicki and her mom. They couldn't be more than 10 years apart in age with Vicki in her late 20s and the mom in her early 30s, only one's dressed like a prudish librarian school marm cliche, and one has really awesome clothes and really radical crimped hair. The other two sequels feature teens that are around the age of 25.
 * The Remake features teens that range from 21 (Brittany Snow) and 22 (Jessica Stroup) to 29 (Scott Porter) and 30 (Dana Davis)
 * The four actors who played the supposedly high-school aged Juan Rico, Dizzy Flores, Carmen Ibanez, and Carl Jenkins in Starship Troopers were between 25 and 30 at the time.
 * In the 2009 Star Trek, most of the cast is semi-plausibly close to the ages of recent Starfleet Academy graduates. However, John Cho is 37 years old, playing the 21-year old Sulu. Karl Urban is also 37, though he's closer to his character's official age of 30. And Zoe Saldana (Uhura) is 31.
 * Harold and Kumar in Harold and Kumar Go To White Castle. Played straight with John Cho, who, at 30, played a character two years out of college - but averted with Kal Penn, who was a relatively age-appropriate 26. By the time the sequel came around, this trope was played straight with both actors (35 and 31 respectively, playing their characters at 24-25 since the action picks up right where the first film left off).
 * Audie Murphy played himself from his late teens to early twenties in To Hell and Back, made ten years later. It wasn't too bad, as he remained quite young-looking as well as short.
 * The first film in the Scream series stars an entire cast of mid-20's actors playing 17-year old students. Neve Campbell and Rose McGowan at 23, Skeet Ulrich, Jamie Kennedy and Matthew Lillard at 26 (older than David Arquette, who plays the 25 year old Dewey) Drew Barrymore being closest to her characters age at 21 years old. Although considering the satiric nature of the film this was probably intentional.
 * The first sequel continues this with Elise Neal as a college student, playing a contemporary of Neve Campbell at the age of 31. The third sequel has a rare aversion with Emma Roberts (who though 20 by the time of its release was 19 during filming), although played straight with Hayden Panettiere (who celebrated her 21st birthday during filming - though she averts this trope elsewhere on this page) and the rest of the cast.
 * Disco Pigs brought us Cillian Murphy, then 24, playing a 16-year old. He was pretty convincing until he was shirtless. (Not that most of the audience probably minded much. Or at least, they normally wouldn't have, but the monologue he delivers while shirtless can come across as rather ... icky.)
 * In Never Been Kissed. Drew Barrymore plays a 25-year old who is pretending to be a high school student, and no one thinks she looks too old. In real life, Barrymore was 23 for the duration of filming. David Arquette, who plays her younger brother, is actually four years older than her.
 * Averted with at least two of her fellow students - Leelee Sobieski and Jessica Alba were 15 and 17 respectively when the film was made.
 * In Taken, the 25-year old Maggie Grace's character is repeatedly stated to be 17, not old enough to leave the country without both parents' permission. Oddly enough, the character's friend is pointedly stated to be two years older than her, though the actress Katie Cassidy is three years her junior.
 * Sometimes the whole point of a character is that it is a child being played by an adult:
 * Pee-wee Herman is an ambiguous man-child who is always referred to as a "boy" but is played by the obviously adult Paul Reubens. In the live Pee-wee Herman Show performed with the Groundlings, as well as Pee-wee's Big Adventure, Pee-wee has a number of friends who are also adults playing children.
 * In Clifford, the 43-year old Martin Short plays the 10-year old Clifford. Forced perspective, body doubles, and oversized props serve to make the character look child-sized.
 * Earlier on SCTV, Short played a TV child star whose show ran on for decades, necessitating oversized props and playing against huge football players.
 * Lampshaded in Better Off Dead when Charles de Mar (played by then-32-year old Curtis Armstrong) says, "I've been going to this high school for seven and a half years! I'm no dummy!"
 * In Sin City 24 year old Jessica Alba (who otherwise generally avoids this trope) played 19 year old Nancy Callahan.
 * In the film adaptation of My Fair Lady, Audrey Hepburn was 34-years old while playing the 21-year old Eliza Doolittle.
 * In For Your Eyes Only, 22-year old Lynn-Holly Johnson played the 14-year old Bibi Dahl, though this was likely done to reduce the Squick of her infatuation with Bond.
 * Lampshaded in What's New, Pussycat? as flashbacks depict Peter O'Toole's pivotal experiences with women in grade school, high school, and college, all with O'Toole in character (his twelve year old self in school uniform looking very Angus Young).
 * For The Chronicles of Narnia: Prince Caspian, 25-year old Ben Barnes was cast as the 17-year old titular prince. (He's 13 in the book.)
 * In Dawn Treader, Eustace is supposed to be 10. He's played by 17-year old Will Poulter. The main four get some of this as well, though not as bad. In the first book, they're 13, 12, 10, and 8. In the first movie, the actors playing them were 18, 17, 14, and 10.
 * Bad Day at Black Rock is one of the most egregious examples ever: 55-year old Spencer Tracy played John J. Macreedy, a World War Two veteran in a movie set in 1945, when Macreedy would in all likelihood have been no older than his mid-twenties, and certainly no older than his mid-thirties.
 * In the film Unfaithful, while a specific age is not given, we are led to believe that Oliver Martinez' character is much younger than Diane Lane (37 at the time of filming). Her husband is shocked at how young he is when he encounters him, and later blasts his cheating wife--"you threw our life away for some f--king KID!". However, Martinez is only a year younger than Lane.
 * Basketball Diaries - 21-year old Leonardo DiCaprio as a teen junkie runaway.
 * Total Eclipse - 21-year old Leonardo DiCaprio as a teen poet.
 * Marvin's Room - 22-year old Leonardo DiCaprio as a teen arsonist.
 * In Catch Me If You Can, 27-year old Leonardo DiCaprio plays real life former con artist Frank Abagnale from age 15 to his mid twenties. However, Abagnale did look much older than his age during that time, which helped him get away with his various cons.
 * In Titanic, Kate Winslet was 21 and playing a 17-year old.
 * Most live-action adaptations of Alice in Wonderland have this problem. The titular role is usually played by a woman at least in her late teens. Alice is supposed to be seven. The youngest actress was at least twelve.
 * The 2010 Tim Burton production plays with the subsequent expectation on the part of the audience, leading us to believe at first that this is just another "adult playing Alice" film only to reveal after she tumbles down the rabbit hole that this is a sequel.
 * Funnily enough, the Disney Animated Canon version used a child voice actress (12-year old Kathryn Beaumont) even though animation provides the perfect excuse for using an adult. Beaumont was also the physical model for the character, so Alice ended up being drawn looking like she was about eleven or twelve rather than seven. Played straight decades later when Beaumont, in her sixties by this time, voiced Alice in Kingdom Hearts.
 * This trope is constantly invoked in porno films: Any actress that qualifies as flat chested is usually cast as a "teenager", even if they've looked like they've popped a couple of kids or have been traveling the strip club circuit for a bit too long. Infamous director Max Hardcore made a cottage industry of hiring short/flat chested actresses, dressing them in toddler clothes, and filming the scenes as if he were making some sort of underground child porn video.
 * Jackson Rathbone age 25 plays 15-year old Sokka (at least in the series) in The Last Airbender
 * In the 1996 film The Craft, coven member 16-year old Rochelle was played by 30-year old Rachel True. The other three 16-year old girls were all played by actresses in their 20s, but were all at least half a decade younger than True.
 * Justin Long has made a career of playing almost exclusively characters a good 10+ years younger than he is. He can make it work though, since he has a rather youthful face.
 * In perhaps one of the most extreme examples of this trope, The Lovely Bones cast 22-year old Rose McIver as the character of Lindsey Salmon, who is supposed to be a 13-year old girl. The incongruity was made even worse by the fact that the character of Susie Salmon, who is Lindsey's 14-year old sister, went to 15-year old Saoirse Ronan, who actually looked like she was about the right age - so the audience was treated to a 22-year old playing the younger sister of an obviously-younger 15-year old. This lead to widespread confusion among audience members as to which sister was supposed to be older.
 * The Carry On Film 'Carry On Camping' featured a school girl played by the 32 year old Barbara Windsor.
 * Used distractingly in Running With Scissors, in which the audience is expected to believe that 20-year old Joseph Cross is Augusten Burroughs at as young an age as about 13. Evan Rachel Wood's character is supposed to be of a similar age, and she's no more convincing. Considering that neither of them look nor act at all like middle schoolers, what age they're supposed to be is straight-up confusing -- and then surprising, once Augusten is stated late in the film to be fourteen.
 * In Goodfellas, Henry and Tommy are played by child actors in the opening fifteen minutes, then the film jumps forward a few years and they are replaced by 34-year old Ray Liotta and 47-year old Joe Pesci. The story covers a period of nearly thirty years, so the choice of actors makes sense (it's considerably harder for someone in their twenties to make a believable 40-year old than in the opposite situation), but it does produce a bit of an "er, what?" moment when the narration identifies Ray Liotta as a "21-year old kid." Similarly Jimmy, played by Robert De Niro who was well into his forties by that point, is first introduced as a 28 year old.
 * In The Lord of the Rings, Eowyn is played by the 30-year old Miranda Otto. Eowyn is twenty-three, at least in the book.
 * A Beautiful Mind: Russell Crowe was in his late 30s while playing the main character. The movie begins as he enters Princeton University, which the real John Nash did when he was 20 years old.
 * Sally Ann Howes was in her mid-30s when she played the 20-something Truly Scrumptious in Chitty Chitty Bang Bang. Years later, she would describe herself as having been "the world's oldest virgin".
 * Scott Pilgrim plays this trope straight with Knives Chau (17) and Stacie Pilgrim (19), both are played by actresses who are (or almost) 25. Making both older than Michael Cera, who is 22. "Young" Neil (20) is a borderline case, his actor is nearly 24. The rest of the cast largely averts this, if their ages are known.
 * 20-year old Sally Thomsett played 11-year old Phyllis in The Railway Children, and was forbidden by contract to reveal her age during the making of the film.
 * In Cherrybomb, the three 16-year old protagonists are played by Kimberley Nixon (who was 22 at the time), Rupert Grint and Robert Sheehan (both of whom were 20). It generally gives the audience a bit of a jolt when Sheehan's character confirms how old they are towards the end of the movie, firstly because the cast are blatantly older than this, and secondly because we've just watched said character engage in a sex-and-drugs orgy and
 * In Precious 16 year old Precious Jones is played by 26 year old Gabourey Sidibe. Not quite that obvious because of the way she was dressed and the fact that Sidibe does not look her age.
 * Kevin Bacon was 25 when he played teenager Ren McCormack in Footloose.
 * Most of the other teen actors are in their mid to late twenties as well. However, Sarah Jessica Parker, who was 19 at the time is more believable as a high school senior than the others. Chris Penn was also around eighteen at the time.
 * The remake looks set to play this trope straight. The "teens" are all comfortably in their twenties, with Ren being played by a 26 year old.
 * In Catch That Kid, Corbin Bleu, Max Thieriot, and Kristen Stewart play 12-year old kids who rob a bank. At the time, the actors were 15, 16, and 14, respectively.
 * The 1981 Italian zombie flick Le Notti del terrore (US title: Burial Ground: The Nights of Terror) has a disturbing example with a then 25-year old midget (Peter Bark) playing a 10-year old child with a serious mother fixation. He not only doesn't look like a child at all, but was cast apparently so they could have a scene where  Ew.
 * 21-year old Georgina Cates lied about her age and pretended to be a teenager in order to play a 16-year old in the film An Awfully Big Adventure. It worked - the cast, crew and director fell for it. Possibly also a subversion, because when Cates first auditioned and gave them her real name and age, she was told she was too old for the role.
 * Harry Earles made a career out of playing short people or children.
 * Gary Coleman often played way younger after playing Arnold Jackson.
 * Bring It On - Some of the actors are in their 20s, most notably Gabrielle Union (age 28) during the first one, and Christina Milian (age 28) during Fight to the Finish. Though the trope was averted with Kirsten Dunst (age 18) and Eliza Dushku (age 19) in the first film, Hayden Panettiere (age 16) in All Or Nothing and Ashley Benson (age 18) in In It To Win It.
 * In the Sleepaway Camp series, some of the teens are pre-teens, some of the teens are teens, some are teens are 20-something, and one is undercover: Angela is pretending to be a teen camper in part 3, and making up various excuses for why she looks old. Some of the excuses are funny, such as mentioning the fluoride in her drinking water, and some are sad, such as when a guy says that she doesn't look like a teen, she must have had a hard life, to which she agrees.
 * The People vs. Larry Flynt - Courtney Love portrays Althea. Althea is 17 years old at the beginning, and Larry just can't believe that she's a day over 18. Courtney Love was 31 and looks it.
 * Nowhere (1996) by Gregg Araki - Mena Suvari and Joshua Gibran Mayweather were both teens, but the rest were between 20 and 40 years old.
 * Friday the 13 th - You'll be hard-pressed to find a real teen in any installment of this teen slasher series.
 * Mirror Mask - 15-year old Helena Campbell is played by 20-year old Stephanie Leonidas.
 * In Girl, Interrupted 28-year old Winona Ryder played the titular 19-year old. Critics at the time mentioned that whilst Ryder did look younger than her age this was still pushing it more than a bit.
 * A particularly ironic example is Logan's Run in which the film's hook is that it's about a society where people are killed once they reach 30. Predictably, much of the cast were well into their thirties and looked it as well.
 * Selma Blair was subject to this a lot.
 * Can't Hardly Wait featured many old teens, especially Selma Blair at age 26.
 * Debutante - 26-year old Selma Blair plays a 17-year old.
 * Girl (1998) - 26-year old Selma Blair plays bookish high school senior Darcy.
 * Cruel Intentions - All of the actors are well out of their teens, especially Selma Blair at age 27 who is supposedly younger than the other characters and has Never Been Kissed.
 * Legally Blonde - 30-year old Selma Blair plays a college student.
 * For more, see the Television section.
 * Earth Angel (1991) was a movie about a prom queen who dies in the 1960s and then has to do a good deed 30 years later. It was seemingly influenced by movies such as Back to The Future and Peggy Sue Got Married, and like those movies, needs actors that can pass as both teenagers and middle-aged people. Of course, no real teens were cast, and most of the actors were in their 30s and 40s, most notably 42-year old Erik Estrada.
 * In Remember the Titans, most of the actors playing the 16-18 year old high school football players were well into their twenties, and Wood Harris was 31, a year older than the actress who played the wife of Denzel Washington. However, Ryan Gosling as one of the players was about 19 and Kate Bosworth as the girlfriend of one of the players was 17.
 * Natural Born Killers - 21-year old Juliette Lewis plays Mallory Knox from ages 15 to 19 (according to the novelization)
 * The Other Sister - 26-year old Juliette Lewis as 18-year old Carla Tate.
 * A Nightmare on Elm Street:
 * 16-year old Nancy Thompson (played by 20-year old Heather Langekamp) fights Freddy, goes without sleep, and has to deal with the death of her teen friends who are also played by people in their 20s. The stress shows on her face, and she looks in the mirror and proclaims, "God, I look 20 years old."
 * There are three actors under the age of 20 in any of the sequels. The actors are usually between 21 and 24. The most egregious example would be Lezlie Deane, playing Tracy in Freddy's Dead at age 27. The youngest teen in the remake was 23.
 * Childs Play:
 * Christine Elise was 25 in Child's Play 2.
 * Katherine Heigl's friends in Bride of Chucky, in their late 20s.
 * In Texas Chainsaw The Next Generation, Renee Zellweger is a 24-year old high school senior. Her friends look older.
 * The Burning Bed covers a specific period in Francine Hughes's life from age 15 to age 29. You would think that they would cast someone around the age of 22, someone halfway between 15 and 29. Instead, they cast 37 year old Farrah Fawcett.
 * Varsity Blues starring the guy from Dawsons Creek and a bunch of other people in their 20s as beloved high school jocks.
 * Devil in the Flesh - 25-year old Rose McGowan plays a teenaged murderess.
 * Dean Koontz's Phantoms - 25-year old Rose McGowan plays a character that was 14 in the book.
 * Jawbreaker - Some high school girls accidentally kill another high school girl during a high school prank. Starring 24-year old Judy Greer, 26-year old Rose McGowan, 27-year old Julie Benz, 28-year old Rebecca Gayheart.
 * The Charlies Angels movie features a flashback montage at the beginning with Charlie's voiceover, "Once upon a time there were three very different little girls..." They then show three adults dressed as girls up to high school age. In the sequel, three years later, they do it again with 28-year old Drew Barrymore, 31-year old Cameron Diaz, and 35-year old Lucy Liu. Apparently, this is humorous.
 * Drive Me Crazy: 23-year old Melissa Joan Hart stars as a teenager with prom problems. Co-starring 23-year old Adrian Grenier as her high school sweet heart.
 * Buffy the Vampire Slayer: 23-year old Kristy Swanson as Buffy, and 27-year old Luke Perry as her high school boyfriend.
 * A Cinderella Story:
 * While averted with Hilary Duff (her character is 17 and she was 16 at the time), this was played straight with Chad Michael Murray, who was 22 and playing a high school senior.
 * In Another Cinderella Story, Selena Gomez was 15 at the time of filming and was therefore younger than her high school junior character. Played straight with 25 year old Drew Seeley playing a high school senior. Drew does kinda look his age while Selena looks somewhat younger than her age, so it's got some squicky vibes when their characters become the Official Couple.
 * Played very straight A Cinderella Story: Once Upon A Song, with 21-year old (at the time of filming) Lucy Hale playing the 17-year old heroine.
 * In The Lost Boys 21 year old Jason Patric played 16 year old Michael, and 16 year olds Corey Haim and Corey Feldman played 12 year olds.
 * Fired Up: has 23 year old Sarah Roemer, 27 year old Nicholas d'Agosto and 30 year old Eric Christian Olsen playing high school cheerleaders.
 * True Grit 1969 has 21 year old Kim Darby playing 14 year old Mattie Ross.
 * Randy Quaid was 23 when The Last Detail was made. It is never specifically stated how old his character is, but he isn't old enough to drink.
 * Wild Things from 1998, 25-year old Neve Campbell and 27-year old Denise Richards as 18-year old high school seniors.
 * Drop Dead Gorgeous from 1999 stars 28-year old Denise Richards as a teen beauty pageant contestant.
 * Clockstoppers has some conspicuously twenty-something teenagers.
 * In 1983, 21-year old Tom Cruise played a teen in four different movies, The Outsiders, Losin' It, Risky Business, and All The Right Moves.
 * Alexis Bledel was 21 years old when she played 15-year old Winnie in Tuck Everlasting (the character had already been aged from a child to a teen in order to accommodate her.) Bledel is now 29 and set to play a teenager in Violet & Daisy - she is thirteen years older than her actually teenage co-star Saoirse Ronan.
 * For The Hunger Games, based on the book series by Suzanne Collins, every young woman in Hollywood seems to have tried out for the lead heroine: a Badass Action Girl named Katniss Everdeen. Winters Bone blonde beauty and new indie darling Jennifer Lawrence has got it. That makes her a 20-year old playing a 16-year old.
 * See also Leven Rambin (Glimmer), who's only a few months older than Jennifer Lawrence.
 * To top it off, Isabelle Fuhrman, who plays Career Tribute Clove, was 14 when they shot the film. Peeta mentions that Careers are always 18. So that means that you have an actress six years younger than her costar playing a character 2 years older than her costar. (Jacqueline Emerson, as Foxface, is also more age-appropriate (she was 16 during production).
 * In Peter Bogdanovich's Mask (no, not that Mask. Dear God, don't mistake these two), the then-24 year old Eric Stoltz played the 15-16 year old Rocky Dennis. Granted, with all the makeup he had to wear to deform his face, it's less noticeable. Somewhat averted with Laura Dern, who was about 18 around the time it was filmed.
 * Ginger Snaps centres around the lives of two teenage sisters; the older sister was played by an actress pretty much dead on the right age (17 or so), while her little sister was played by a young-looking actress, four years older than her screen sibling.
 * Both Inverted Trope and played straight in Scrooge, where both the elder Scrooge and his young self were played by Albert Finney, then in his early 30's.
 * The actors in Three O'Clock High.
 * Deux. This French film stars Isabelle Huppert as twin sisters in an extremely confusing storyline that jumps crazily backwards and forwards in time and space, with no attempt to make Huppert look appropriately older or younger. There are a couple of lengthy sequences in which she appears as a schoolgirl, despite being in her late forties. In addition her/their mother, played by Bulle Ogier, is seen in flashback as a young heavily pregnant woman despite being in her sixties.
 * Take Me Home Tonight is about a group of characters in their early twenties but much of the cast is ten years (or more) older. Anna Faris and Dan Fogler in particular were both 34 playing fresh university graduates. The difference in appearance between them and those characters who are played by actors in their early/mid twenties is quite jarring.
 * I Love You Beth Cooper was filmed the year Hayden Panettiere, as the titular high school cheerleader, turned 19. So far so good. Unfortunately Paul Rust, the "I" in the title, was almost 30...
 * The end credits feature high school pictures of the main cast and the above-the-line crew; Panettiere is just about the only one of the former (and it's safe to say the latter, unless there's something Twentieth Century Fox isn't telling us) who looks the same as she did working on the movie!
 * To an extent in Mystery Team. Granted, the characters are 18, so it's far less noticeable.
 * The Conspirator features 42-year old Norman Reedus playing Lewis Payne who was 21 at the time of his death.
 * The 2009 Fame remake has numerous examples: Victor (played by Walter Perez, age 27), Denise (Naturi Naughton, 25), Marco (Asher Book, 21). The actors closest to the actual age of the characters they play are Kherington Payne (Alice) and Kay Panabaker (Jenny), both 19.
 * In Breakfast On Pluto, Cillian Murphy plays Kitten both as an adult and as a teenager, and makes a pretty good teenager for an actor in his early 30s. Of course, playing a 16-year old is much easier than playing a drag queen.
 * Don't forget the film for Disco Pigs, where Cillian played a 16-year old when he was 24 at the time. It is rather justifiable, as he actually looked very convincing, and he did play the character in the stage play version at 19 years of age.
 * The Peter Jackson film Heavenly Creatures has Kate Winslet and Melanie Lynskey playing 14 year olds when they were 19 and 17, respectively. Probably out of a legal necessity, as there was a lesbian love scene in the film.
 * Christine Taylor (Marcia), Jennifer Elise Cox (Jan), and Christopher Daniel Barnes (Greg) were all in their twenties when cast in the mid-90s Brady Bunch movies. Interestingly, Cox is actually older than Taylor in real life, despite playing her younger sister.
 * In Rob B Hood, Jackie Chan, who was 52 years old in 2006, nevertheless plays a professional burgler with family problems who ends up having to care for a baby for several days. He engages in his usual acrobatic and martial arts stunts alongside his co-star Louis Koo, who plays Chan's character's partner-in-crime, who is 16 years younger than Chan.
 * Breaking Away: The four lead characters are supposed to be 19. Jackie Earle Haley was 17 at the time, then there was Dennis Quaid (25), Dennis Christopher (24), and Daniel Stern (22).
 * Caroline Munro played a high school student in the 1986 slasher flick Slaughter High. Munro was born in 1949. You do the math.
 * In Warlock, a 30-year old Lori Singer played a 20-year old character.
 * Johnny Depp was 46 when he starred as John Dillinger in Public Enemies. The real John Dillinger was killed at the ripe old age of 31.
 * Anna Paquin was roughly 23 when she played a seventeen year old in Margaret. Due to the film going through a lengthy period of post-production Development Hell, she was 29 when it was finally released in 2011.
 * David And Lisa, 1962, starred then 26-year old Keir Dullea and 19-year old Janet Margolin in the title roles -- respectively sixteen and thirteen.
 * Stand and Deliver features a 25 year old Lou Diamond Phillips playing a high school senior.
 * Wet Hot American Summer has hilariously age inappropriate actors including Amy Poehler and Paul Rudd playing high school aged camp counselors. I believe it was intentional.
 * The casting of Moonstruck is all over the place in terms of age. Cher was a 42-year old playing a 37-year old (not a stretch). Danny Aiello was 54, playing a 42-year old. Nicolas Cage was just 23, and although the age of his character is never mentioned outright in the film, the plot (involving his romance with Cher's character) just wouldn't make much sense unless we assume he's significantly older, at least mid-30ish.
 * Played with quite a bit in the movie of Twenty One Jump Street:
 * Justified: As with the series, the main characters are adults passing off as teenagers to investigate youth crimes. Jonah Hill somewhat looks the part, even at 27; but Channing Tatum is over thirty and looks like it.
 * Not quite as Hill and Tatum are still at least a few years older then the real age of the characters they are playing which is 24 or 25. Hill not as bad at about 27 at the time of filming but Tautum over 30
 * Lampshaded: Channing's character is handwaved as having repeated two classes; similarly, his secret identity is supposed to have repeated a year., he's called out three times as looking too old.
 * Inverted: On the other hand, Channing's character accuses another student of looking too young: this particular character is indeed a 15-year old actor... playing a senior in high school.
 * Played straight: With the rest of the "high-schoolers" cast, especially the main drug dealer played by 26-year old Dave Franco which if he played one of the title characters he would still be playing this trope slightly straight as Tatum and Hill's characters graduated in 2005 Franco likely graduated in 2003 based on his age.
 * La Reine Margot stars Isabelle Adjani and Daniel Auteuil, who were 40 when they played a queen and king who were historically 19. Auteuil shows his age, but many have expressed surprise that Adjani was any older than her twenties.
 * Portrait of Jennie: When introduced, the titular character is about 13 and played by a 29-year-old Jennifer Jones.
 * The casting of the title role in 1984's Supergirl isn't too bad by the usual standards of this trope; Helen Slater was 20 at the time, playing a high school age girl. But her roommate Lucy Lane? Actress Maureen Teefy was 31 at the time the movie was made!
 * In Bunraku, teenage Momoko is portrayed by 25 year old Emily Kaiho, who sort of pulls it off by being fresh-faced and petite.
 * Much is made of how Yoshi is the youngest of the protagonists, and inexperienced and hot-headed as a result. Gackt meanwhile is pushing forty (but looks twenty years younger).

Live-Action TV
"Duncan: She's like our age. Veronica: She's twenty-five."
 * Arthur Fonzarelli in Happy Days was supposed, in the early episodes at least, to be seventeen years old. The Fonz was played by Henry Winkler, who was twenty-nine when the show started, and thirty-nine when it ended. His age seemed all the more obvious when he was seen romancing an actress clearly in her teens or twenties.
 * Back to the Trope Namers, Dawsons Creek: Much worse than Dawson's leads were the actors introduced later on: Kerr Smith (26) and Meredith Monroe (29) playing siblings (and high school sophomores) Jack and Andie McPhee starting in Season 2. Worse considering that Andie was likely the younger sibling.
 * On the behind-the-scenes parts of the Series Finale movie, James Van Der Beek was amused that it was the first time he and Dawson were the same age (because there was a five-year time skip from the last episode to the movie).
 * The Creek was not the worst offender. That title might well go to Buffy the Vampire Slayer, where the tenth-graders (16-year olds) were played by Nicholas Brendon as Xander (25), Alyson Hannigan as Willow (22) and Charisma Carpenter (26, making Carpenter the same age as her teacher played by Robia LaMorte. Possibly lampshaded when Wesley first meets her and mistakes her for a teacher.). On the show's spinoff, Angel, the role of Angel's 16-year old son Connor was portrayed by then-22-year old Vincent Kartheiser.
 * The most jarring example from the series might have been when 27 year old Elizabeth Anne Allen played a 16 year old cheerleader (then again Allen is actually several months younger than Carpenter).
 * Also Oz and Jonathan, played by 23-year olds Seth Green and Danny Strong. Also appearing was 26-year old Jason Hall as 18-year old Devon. Though the show did feature 18-year old Mercedes McNab as a teenaged Harmony later in its run.
 * Sarah Michelle Gellar, who was 19 when she began playing a 16-year old Buffy, was the only one of the leads who was actually (just about) a teenager at the time of her casting.
 * James Marsters as Spike played the role from 1997 (when he was 35), reprising the role in Angel up until 2003 (When he was 42) playing a character who was implied to be of similar physical age to characters like Buffy. Somewhat averted due to his being a vampire and hundreds of years old.
 * Averted however with Dawn, played by an actress of the correct age (who eventually ended up taller than Sarah Michelle Gellar).
 * Though she was originally intended to be a preteen, which is very clear in the first few episodes she appears in, before the scripts were written with Michelle Trachtenberg in mind.
 * Beverly Hills, 90210 is well-known for this sort of thing, but believe it or not, quite a few of the cast members were actual teenagers. Of course, some of the core cast of high school juniors (ages 15-16) were well into their twenties: Luke Perry (25), Ian Ziering (26), and, most famously, Gabrielle Carteris, who was 29. Series star Jason Priestley was comparatively young at 21. Still, these examples alone are so Egregious, coupled with the fact that 90210 predates the Trope Namers by several years, that it is also called "90210 Syndrome".
 * This trope is played ridiculously straight on the reboot 90210. The youngest cast members were 19 when the series started, and the rest range from their early twenties to Trevor Donovon who was 30 when he began his stint. Honorable mentions are Michael Steger (28 at the beginning) and Matt Lanter (25 at the beginning). What's even crazier is that those three "teens" are all older than actor Ryan Eggold who plays the English lit. teacher!
 * Inverted in Samurai Sentai Shinkenger with 14 year old Runa Natsui playing 17 year old Kaoru Shiba
 * Inverted with Hiknin Sentai Akibaranger with 16 year old Karin Ogino playing 23/24 year old Yuko Yamada aka Yumeria Moegi
 * Justified and Lampshaded in that she's supposed to look much younger then she is.
 * 22-year old Justin Long in Ed.
 * 23-year old Lauren Ambrose plays highschool-aged Claire from Six Feet Under.
 * Senta Moses is an actress who is very short and has very curly hair... which contributed to her playing a 17-year old at age 27 on the show Bull. She wasn't alone on this part, however: Her 16-year old brother was played by 25-year old Fred Koehler.
 * Similarly, she played a 16-year old computer genius in an episode of Vengeance Unlimited two years earlier (at 25).
 * And in 2009, at 35, she's playing an apparently early 20-something computer tech on General Hospital.
 * Roswell: not one of the members of the younger cast (supposedly 16-17 at the start) was a teenager, with the exception of 18-year old Majandra Delfino and Emilie de Ravin. Shiri Appleby, Nick Wechsler and Katherine Heigl were 20, Brendan Fehr and Colin Hanks were 21 and Jason Behr was a whopping 25 years old when the first season premiered.
 * 24-year old Tom Welling, and (let's face it) pretty much everyone else from Smallville, except Lex Luthor, who is supposed to be several years older. But Tom is particularly noticeable, as the character is fourteen in the pilot. How many fourteen year olds are built like a tank?
 * In one episode, Lex was stalked by a servant girl about 10 years younger than he. She was played by Azura Skye, who in real life is indeed about 9 years younger than Rosenbaum; but in Zoe Duncan Jack And Jane she played his fraternal twin sister.
 * Although Kristen Kreuk, and Allison Mack were just barely 18 at the start. Michael Rosenbaum was 29 playing the supposedly 21-year old Lex. It doesn't seem so bad once you get out of the teen years.
 * Sam Jones III (Pete Ross) was also 18 at the start.
 * Tom Welling is two years older than Brandon Routh (Clark/Superman in Superman Returns), yet plays the same character at a much earlier point in his life (although admittedly in a different continuity). Welling also began playing Clark at about the same age (maybe a year younger) that Christopher Reeve made his screen tests to play Superman in the mid-1970s.
 * 31-year old Gerard Christopher was cast as the title character in the live-action Superboy series which ran from 1988-1992. Superboy/Clark Kent was supposed to be a 19 or 20-year old college sophomore at the time.
 * 25-year old John Hensley playing 16-year old Matt on Nip Tuck (made glaringly obvious off-screen when Hensley began dating Joely Richardson, the actress, only 13 years his senior IRL, who played his mom on the show). Also made glaringly obvious when he started getting a receding hairline.
 * The OC is guilty of this, as mentioned in the quote at the top, with teens in their late 20s and parents in their early 30s.
 * The OC hangs a lampshade on this trope, among many others, with their show-within-a-show, "The Valley."
 * The teenage characters of The Vampire Diaries are played by 20something actors, starting with Nina Dobrev (20), Steven R. McQueen (21), Katerina Graham (20), Caroline Accola (22), Kayla Ewell and Zach Roerig (both 24). All of them play high school students. Stefan and Damon Salvatore, who got vamped at the ages of 17 and 24 respectively, are played by Paul Wesley (27) and Ian Somerhalder (31).
 * This is rendered extra absurd by the fact that 22-year old Sara Canning plays an aunt (albeit a young one) to Dobrev and McQueen's characters, when she is younger than some of the actors who play their classmates.
 * Popular, from 1999, about high school students played by 20-something-year olds, most notably 28-year old Leslie Grossman and 29-year old Ron Lester.
 * Possibly intentional as it something of a parody of High School Dramas
 * In their junior year (season one), when you would expect them all to be about 16 or 17, some of the main characters of Veronica Mars were: the titular heroine (24-year old Kristen Bell), Wallace Finnel (22-year old Percy Daggs III), Logan Echolls (22-year old Jason Dohring), and Dick Casablancas Jr. (23-year old Ryan Hansen).
 * Which worked fine, except for the episode in season two, in which then 24-year old Kristen Bell and 25-year old Aaron Ashmore (Troy), playing high school seniors (~18), interact with 18-year old Michael Cera and 17-year old Alia Shawkat... who were playing college students. One of them at least in his sophomore year, as he was acting as a tour guide to profros. That was sort of disorienting.
 * The series actually had an even more prominent example in the first season; Amanda Seyfried was only 18 when the series started, yet Lilly was supposedly a year older than Veronica (and all of her contemporaries -- again, as noted above, played by people in their 20s). Then again, Seyfried's voluptuous figure (which the writers and directors were not afraid to draw attention to) helped her look more developed than Bell, even though Bell's face was more mature. Which is interesting in light of Seyfried's role in Mean Girls (see above), made the same year.
 * There was also Charisma Carpenter who played the 25-year old Kendall when she was 35 and clearly looked like she was in her thirties. The show was not above indulging in a little meta humour about all this:

"Joey: Come on, am I 19 or what? Chandler: Yes, on a scale from 1 to 10, 10 being the dumbest a person can look, you are definitely 19."
 * However, it's later found out that
 * Even then
 * Kind of lampshaded in the mini-episode shot to promote a possible season 4. Veronica is supposed to be in her mid-twenties, having graduated both college and the FBI academy, yet as one of the younger new recruits, she gets picked to go undercover as a teenager.
 * iCarly: The actor who played Gibby inverts the trope, being 3 years younger than the character when introduced. The filming schedule stretch has actually brought both the character and the actor to almost the same age, and the actor is going through the same growth spurt that Freddie went through in between Season 1 and Season 2.
 * Griffin, Carly's love interest in "iDate A Bad Boy", was played by a 23 year old and looked like it, especially in some shirtless scenes, is supposed to be a high school senior. The episode involved some heavy make out sessions with the star of the show Miranda Cosgrove, who was 15 when they filmed them. Miranda apparently got to choose which guy they casted.
 * On Big Time Rush, Carlos Pena (21), Logan Henderson (21), James Maslow (20) and Kendall Schmidt (20) play 16 year olds. It sort of works out, though, because of their rather boyish yet still mature good looks and their mid-pitched voices. Kendall and Carlos could pass as a bit older, though.
 * This trope is subverted in Twenty One Jump Street, where the main characters are clearly identified as adults, but they are assigned to this undercover unit because they all look young enough to pass as teens.
 * Julianna Rose Mauriello was 13 when she took on the role of 8-year old Stephanie on the children's show LazyTown, and is still playing her at 17. By the second season, filmed when she was 15, it was obvious that Julianna was no longer a little girl, and in LazyTown Extra, filmed when she was 17, the character mentions she's lived in LazyTown for a year, which would make her 9.
 * And if rumors are to be believed, LazyTown is returning in 2011 and might even have Julianna reprise her role as Stephanie...despite the fact that she is now 20 years old and will still be playing a 9 year old.
 * Power Rangers is a common offender, with the original season's 15-year old characters being played by actors as old as 24. Operation Overdrive had an 18-year old Smart Chick being played by a 28-year old actress (who, however, looks quite young and seems to actually be able to get away with it) and a guy of 19-20 being played by a 29-year-old.
 * The early seasons had most actors between 18-21, with subsequent seasons going off in many different directions.
 * Mighty Morphin Power Rangers has an excuse: the characters were originally intended to be high school seniors, as evidenced by the original plot for the two-part episode 'Doomsday' involving the Rangers going to Senior Prom. When the show became a hit, they needed to keep the characters around, so they refrained from actually giving ages for the Rangers in order to keep the high school setting as long as possible.
 * Though in that case, the trope still would've been played straight as several of the actors were a few years older than a high school senior. The trope would've been averted, though, with Austin St. John, who was 18 at the time.
 * The 28-year old actress from Operation Overdrive has stated in interviews that she was also given an audition for the Harry Potter films as 15-year old Cho Chang...
 * Melanie Vallejo, who plays the 17/18-year old Madison in Mystic Force, was 27 at the time of filming...
 * Played straight and inverted in the case of Olivia Tennet (Dr. K) from RPM, in which the 17-year old actress (when production began) played her character at ages 14 (during a flashback in "Doctor K"), 18, 19 (as of "The Road to Corinth"), and then 20 (as of "If Venjix Won").
 * Linkara summed it up nicely in his History of Power Rangers series: "Clearly, the casting director has never seen a teenager."
 * Both Disney Channel and ABC Family loves to use this every now and then. And yes, they're not ashamed to use it.
 * Lizzie McGuire mostly avoided this with the main characters, but Adam Lamberg (who played 14-15 year old Gordo) was a college student. Kyle Downes (who played Tudgeman, in the same grade as Lizzie et al) is even worse...in his previous series (Higher Ground) he played a troubled high schooler.
 * Hannah Montana has Jackson Stewart, who is (currently) depicted as a high school senior, while Jason Earles (who plays Jackson) is actually,
 * Likewise, The Suite Life of Zack and Cody also premiered in 2005, with then 20-year old Ashley Tisdale playing then 15-year old Maddie Fitzpatrick. The show is also a subversion, as Dylan and Cole Sprouse were (and continue to be) exactly the same age as their characters, which actually required some suspension of disbelief, as their voices took some time to crack.
 * Slightly inverted on The Secret Life of the American Teenager: Some cast members actually were teenagers when the series started (the youngest being 15 (India Eisley, at the time the show was first aired)), and were only a couple of years older than their characters. Played straight with other members of the cast who were all in their early twenties from the get-go (the oldest member being a then 24-year old Greg Finley playing a high school sophomore).
 * Lampshaded in the TV version of Ten Things I Hate About You. The overprotective father refers to Patrick as "your friend with the disturbingly deep voice who looks much older than seventeen." His actor, Ethan Peck, is 21 years old. In this case, the whole casting thing doesn't really work, since he does indeed look like a college student.
 * Indeed, the only teenage role actually played by a teenager is 16-year old Bianca, played by 18-year old Meaghan Martin.
 * That's So Raven had very obvious examples of this: Raven-Symone was 18, Orlando Brown was 17, and Anneliese van der Pol was 19 and they were all playing high school freshmen.
 * Pretty Little Liars. The four main characters are 16 but their actresses are between the ages of 20 and 25. The most egregious example is the character of Maya, who is 16 but is played by 31-year old Bianca Lawson.
 * Bianca Lawson was in Saved by the Bell: The New Class, a show that is even older that the Trope Namers, actually. This fact raises this example Up to Eleven.
 * The four main teen characters on Make It or Break It are played by actresses between the ages of 20 and 25.
 * Chelsea Hobbs, who was 24 when she began playing Emily Kmetko, was already a mother.
 * Even Stevens used this heavily. Applies to the entire cast to a significant but albeit mostly believable degree, but especially Egregious with Donnie, a star athlete in high school played by an actor in his mid-twenties, and Ren, a 13-14 year old middle school student whose actress was well into high school age.
 * Made even worse that the two seasons the show ran kept them the same age.
 * A funny example is when Shia Labeouf was cast a 12 the same age as Lewis was, a pilot was filmed. By the time the show was fully in production after having been in Development Hell for a couple of years Labeouf was noticeably older. This is most apparent in The season 1 finale which uses footage from the pilot as a flashback. Lewis looks years younger besides the events of the flashback taking place likely only a few months prior as it's Lewis first day of 7th grade which he is in for the duration of the show.
 * Tiffany Thorntoni, the actress that plays Tawni Hart in Sonny With a Chance and now So Random was born in 1986 (26). Tawni can't be older than 17.
 * ANT Farm's cast members all fall in this: China Anne McClain (age 12), Sierra McCormick (age 13), and Jake Short (age 14) play 11-year old Freshmen, and Allie DeBerry (age 16) is just one age up compared to her character Paisley, who's age 15 in the show.
 * Doctor Who had numerous examples:
 * 23-year old Carol Ann Ford as 15-year old Susan Foreman (though she is a Time Lord).
 * 21-year old Maureen O'Brien as 15-16-year old Vicki.
 * 25-year old Jackie Lane as 18-year old Dodo Chaplet.
 * 21-year old Wendy Padbury as 15-year old Zoe Heriot (just to add to the confusion, according to The Brigadier she looks "about 19").
 * And again at the age of 27 in the stage adaptation "Seven Keys To Doomsday", she played 17-18-year old Jenny Wilson.
 * 23-year old Mark Strickson as Turlough. This one is perhaps less Egregious, as Turlough was actually an alien of indeterminate age, but he was posing as a human boy in boarding school, and did not look young enough at all. For that matter, neither did most of his classmates.
 * 26-year old Sophie Aldred as 16-year old Ace.
 * The new series two-parter The Doctor Dances/The Empty Child has a subversion.
 * The spinoff The Sarah Jane Adventures features 20-year old Daniel Anthony as 14-year old Clyde Langer and 18-year old Anjli Mohindra as 15-year old Rani Chandra.
 * K 9 features 19-year old Keegan Joyce as 14-year old Starkey, 16-year old Philippa Coulthard as 14-year old Jorjie Turner, and 20-year old Daniel Webber as 15-year old Darius Pike.
 * Melissa Joan Hart started playing 16-year old Sabrina the Teenage Witch when she was 19-20 (depending on when it started filming, she was 20 when it first aired). By its final season she was 27, though by then she'd been going to college and then on to a career in journalism.
 * This is actually a good example of how the line blurs as actors and characters grow older, although this effect only happens in works where the characters age roughly in realtime.
 * Additionally, when she was 15 she played the role of the similarly aged Clarissa Darling in Clarissa Explains It All which ran from 1991 to 1994.
 * In Terminator: The Sarah Connor Chronicles, 26-year old Summer Glau played Cameron Philips, who is able to pass as a high school student. Cameron's cyborg form is patterned after a teen named Alison. And one assumes that all teens from the future live a harsh life that causes crows feet and deep smile lines, as seen on Summer Glau's face in closeups.
 * A reporter for Boston's Fox affiliate referred to Glau and costar Thomas Dekker as the show's "teen stars" in a promo for an interview segment. Dekker was 20. He was however, never supposed to be a teenager in the show.
 * Except for those little details about attending high school and celebrating his 16th birthday at the end of S1.
 * In a second season episode, Cameron was seen being served alcohol in a bar. It's likely she has IDs to cover a wide variety of ages.
 * Similarly, but less drastically, is Summer Glau's portrayal of River Tam in Firefly. Summer was 21 (23 during the filming of Serenity) but River was only seventeen. And in the R. Tam Sessions, it went even further, with Summer playing River when she was fourteen years old. Surprisingly, she plays all these ages quite convincingly as she still looks very much like a teenager now.
 * She's actually a year OLDER than Jewel Staite, who played Kaylee and would have been about 19 during shooting. To be fair, no official age is ever given for Kaylee, but it's presumably at least a few years older than River.
 * In Terminator 2, Sarah Connor is called "29 years old" in an APB. Since her son (conceived in the first movie) is now 10 (played by 14 year old Edward Furlong). She would have been 19 at the most in the first movie. Linda Hamilton would have been 28 at the time.
 * According to the Novelization, this is exactly right - the first section to focus on (the right) Sarah gives her age as 19.
 * Battlestar Galactica Reimagined plays this straight with Sharon Valerii, who is supposed to be younger than Kara Thrace. In real life Grace Park, who plays Sharon, is actually six years older than Katee Sackhoff as Kara.
 * Actress Rachel True played teenagers when she was in her early 30s and young twenty-somethings when she was in her late 30s to early 40s.
 * In Half Baked, at 32, she's girlfriend to 25 year old Dave Chappelle. Of course, her character's age isn't given, and this editor doesn't see why he couldn't date a chick seven years older than him, especially as Hollywood does the inversion of that all the fucking time.
 * Trina McGee started playing high school senior Angela Moore on Boy Meets World at age 28; this is really glaring because every other major cast member was more-or-less age-appropriate.
 * Strangers with Candy - 30-something Amy Sedaris plays 40-something Jerri Blank, who decides to go back to high school as a freshman. Jerri doesn't lie about her age, and this trope is mostly inverted by casting actual teens as the students to make the situation seem even more ridiculous. Until the last episode, when 30-year old Winona Ryder played "Fran" the coolest girl at school.
 * Will Smith was 21 when he played the 16-year old titular character of The Fresh Prince of Bel Air.
 * His music had already established that trend, with story songs placing him in the role of a young teen in high school even though he was in his late teens and early twenties at the time.
 * Chiara Zanni, who plays the main character "Amy" on The N show About A Girl, was 29 years old during filming, yet she plays a supposedly "young college student."
 * Gary Burghoff of Mash fame. He was already 27 when playing the teenaged Radar, and continued the role well into his 40s. Burghoff, however, had such a childish frame and voice, that little besides his thinning hairline betrayed his true age. The producers tried hard to get him to keep his hat on in later episodes.
 * There was a heavy dose of Dawson Casting for most of the cast, especially in the later seasons. The book establishes Hawkeye as 28 years old, but TV-Hawkeye was played by Alan Alda, born in 1936 -- 36 when the series started (which would have made Hawkeye of draft age during WWII), 47 by the time it ended.
 * This, combined with the fact that the show lasted almost four times as long as the war it portrayed, gave rise to some excellent accidental Fridge Brilliance: along with other signs of aging, Hawkeye's hair went from jet black to pure grey over the course of the show -- reflecting the effects of the stress and horror of war. A healthy, 28-year old actor wouldn't visibly age much in three years, but a stressed, overworked, mentally frayed, constantly terrified 28-year old frontlines army surgeon would take about three years to age as much as a healthy, 36-year old actor would in eleven years.
 * Subverted in an episode of Law and Order Special Victims Unit which featured an adult conwoman who posed as a teenager in several different high schools . As many other cases, the plot was Ripped from the Headlines: see it here.
 * In an episode of Law and Order with a similar plot, the female murderer is played by a 20 year old actress. The character is a 26 year old woman pretending to be a 16 year old girl.
 * The Ripped from the Headlines (sort of) precursor of the above, an adult writer posed as a teenager in order to sell her scripts; naturally this was made into TV movie.
 * In CSI: NY.
 * All of the secondary school pupils in the seventies Britcom Please Sir were quite visibly in their late twenties or early thirties.
 * Nog, in Star Trek Deep Space Nine was supposedly a young teenager, but played by Aron Eisenberg, who was in his twenties when the series started. This is, however, something of an odd aversion: he was cast because a kidney transplant in his youth stunted his growth and they wanted him to remain short, since Ferengi are smaller than other humanoids. However, it got incredibly jarring, because his best friend Jake (whose actor was two years older than the character, but didn't look it) had some crazy growth spurts and ended up being 6'3" by the time the series ended. I guess they didn't expect Nog to stick around as a recurring character for that long.
 * Wil Wheaton was 15 when playing a 15-year old Wesley Crusher. Star Trek in general has avoided this with the child characters, with several recurring children on Star Trek Voyager being played by the appropriate age.
 * One of the worst examples was the Original Series episode "Miri". The "kids" in that would have died if they'd hit puberty (so "early" blooming cannot explain this away)--but some of them looked like they were in their thirties. Or older.
 * The best-known Dawson Casting in the Original Series might be Chekov, who was supposed to be 21 years old when 31-year old Walter Koenig joined the show in 1967.
 * The 2009 movie retcons this by giving him a birthdate that would have made him 26 when he debuted in the show.
 * In Heroes, Nicholas D'Agosto was 27 years old when he started playing high school student West Rosen.
 * In "Five Years Gone" and other episodes set in an alternate future, Claire doesn't look notably older.
 * Period drama Upstairs, Downstairs is an interesting case of Justified Trope Dawson Casting: at the beginning of the series, Elizabeth Bellamy is 17, played by 26 year old Nicola Pagett. But there are frequent Time Skips forward, making the character around 29 at her final episode.
 * Pauline Collins is several years older than the age of her character, Sarah, in the first few episodes, but like Elizabeth, they line up better by her last episode. It seems less egregious with an adult actor, because it's perfectly legitimate to cast someone according to the age she appears, rather than her actual age, and Collins did look younger than she was.
 * J.D. Williams was 24 when he began playing then-16-year old Bodie Broadus on The Wire. Julito McCullum was 17 when his character (Namond Brice) was 14, and Tristan Wilds was 18 when his (Michael Lee) was 14. Other characters were exceptions to this trope (see below).
 * Another surprising example from The Wire: Lt. Daniels is the apparently forty-ish squad commander, and Carver is the late-twenties junior officer. But their actors, Lance Reddick and Seth Gilliam, were both in their mid-thirties at the start of the show, and Gilliam is actually a year older than Reddick.
 * Another adult example is the 35 year old Michael K Williams as the approximately-28 year old (in season one) Omar Little. This seems like a fairly trivial age gap, but it seems more striking when paired with Ernest Waddell (who is almost twenty years younger than Williams, making him 17 during the filming of season 2), who played Omar's lover Dante in seasons 2 and 3.
 * The TV adaptation of Gossip Girl is chock full of this. Spoofed on The Daily Show after the 2008 Olympics scandal of the Chinese gymnasts possibly being underage; Stewart questioned how qualified Americans are to judge such a thing with a shot of the GG cast.
 * On the other hand, many people are surprised to learn that Taylor Momsen is the same age as her character.
 * Which actually ended up causing problems when Chace Crawford objected to his character's romance with Momsen's character, because while the characters were only two years apart Momsen was fifteen and he was twenty-three. They ended up scuppering the pairing because of how uncomfortable he was with it.
 * At 26 years old Keiko Agena played the then 15- or 16-year old character Lane Kim in the television series Gilmore Girls.
 * Milo Ventimiglia was 25 when he started playing 17-year old Jess.
 * Party of Five had the (then) 26-year old Scott Wolf and 20-year old Neve Campbell playing the respectively 16- and 15-year old Bailey and Julia. On the other hand 11-year old Lacey Chabert (Claudia) and 16-year old Jennifer Love Hewitt (Sarah) were the same ages as their characters.
 * Lampshaded in season 3 where Bailey's friend, seeing his fake ID, was very surprised that anyone would believe he's 27.
 * Due to the fact that time on the show passes much slower than in real life, 10-year old Walt Lloyd on Lost was played by roughly 14-year old Malcolm David Kelly in season 3, who was 12 when the series began.
 * They try to disguise his aging... but in the season 4 finale, they don't disguise it, since, which still doesn't work because he's too old for . Prior to his appearance in he had appeared a few times and the show began to lampshade the changes to Walt, for instance Locke described how Walt suddenly showed up, but was taller, more so than the few months that had passed on the show to explain.
 * Inverted to the point of absurdum on Rome where Vorena the Younger and little Lucius are played by children under the age of ten throughout the series, in spite of nearly 20 years passing from the pilot to the finale. Especially odd when Octavian ages properly, and when Caesarion, who is born when Lucius is at least four or five years old, appears to be played by someone older than the actor playing Lucius when he appears in the second season.
 * The cast in The Middle are a lot older than they actually are. However to be fair, Brick's actor (Atticus Shafer) has Type IV Osteogenesis Imperfecta and is a lot shorter than someone his age would be otherwise.
 * The star of Nickelodeon's The Mystery Files of Shelby Woo was extraordinarily unconvincing as a "kid detective," even to the target audience.
 * A five year Time Skip between the 4th and 5th seasons of Desperate Housewives has led to this trope being inverted for several of the characters: 23-year old Danielle Van de Kamp and 24-year old Julie Mayer are now several years older than the actresses playing them (19-year old Joy Lauren and 18-year old Andrea Bowen).
 * The television version made in Italy in the '70s of the book Il Giornalino di Gian Burrasca(Johnny Whirlwind's Diary) have 30-year old people as 6-year old children.
 * Parodied in an episode of Friends, where Joey tries to play a 19-year old, but he is absolutely unconvincing.

"I want to live in Dawsons Creek, where the kids are in their 20s and their parents are in their 30s."
 * Also played straight on Friends, as every flashback to (and video evidence from) Ross, Monica, and Rachel's high school days featured the regular actors playing themselves at 18.
 * Jeeves and Wooster has it both ways. Both Hugh Laurie and Stephen Fry were in their early 30s when the series started in 1990. The ages of the characters are never given in the books, but it would seem that Bertie Wooster (Laurie) was in his early-to-mid 20s and Jeeves (Fry) in his 40s. Of course, their ages are never given in the series, either, so Powers That Be could get away with it. By way of contrast, the Jeeves movies of the mid-1930s starred 40-year old Arthur Treacher as Jeeves and 25-year old David Niven as Bertie.
 * The WB's Jack & Bobby featured 24-year old Matt Long as 15-year old Jack McCallister. Made glaringly obvious by the fact that Logan Lerman, who played Jack's 13-year old brother Bobby, was actually 12 at the time of filming.
 * Will and Grace jokes about this with Jack saying.


 * In BBC sitcom Open All Hours, David Jason plays Granville, nephew and errand boy of Ronnie Barker's Arkwright. Jason would have been around 35 when the series proper started and 44 or 45 when it finished. In itself, it's not technically implausible that he could be Barker's nephew (even without stretching their ten year age difference). However, although never(?) explicitly mentioned, none of Granville's character (obviously meant as young and inexperienced), the generational dynamic between the two leads and their obvious statuses- and the fact that no-one thinks it strange that he's still doing an errand boy job - makes any sense until you realise that Jason is playing a character around half his real age.
 * Kal Penn was 29 when he played a high school student in Season 6 of Twenty Four.
 * Elisha Cuthbert was 19 when she started playing Kim Bauer, who was sixteen at the time of Season 1. As of Season 7, she's 27 and her character's 34!
 * One episode of Psych quite possibly took advantage of this trope.
 * The plot of Caprica revolves partially around two 16-year old girls. Of the actresses who play them, one was 21. The other was 23.
 * The Canadian sitcom Life with Derek premiered in 2005 with lead characters Casey (15) and Derek (16) played by then 19-year old Ashley Leggat, and then 18-year old Michael Seater, respectively.
 * On the UK "dramedy" Shameless 21-year old Fiona Gallagher was portrayed by then 33-year old Anne-Marie Duff. In an interview, the actress herself admitted that she was surprised to have been offered the role, as she thought she was "too old to be seen for it."
 * Duff was 30 years old when she appeared in The Magdalene Sisters as Margaret, who ages from 16 or 17 to 20-ish. The film also starred the then 25-year old Eileen Walsh as teenage Crispina.
 * Burt Ward, the teenaged Robin: The Boy Wonder in the 60's Batman, was already 20 when the show started filming.
 * The 16/17 year old Baker twins in Privileged skirt this trope - while at the time of first airing (in 2008) Lucy Hale (Rose) was only nineteen, Ashley Newbrough (Sage) was almost 21. Also, main character Megan Smith is supposed to be 23, while Joanna Garcia was 29 when the show first aired.
 * Some of the younger patients on House have this. One example is the 15-year old supermodel in the 2nd season episode "Skin Deep" played by an actress aged 25.
 * Several of the doctors on the team invert this to some extent, at least presumably, being played by actors who would be extraordinarily young to be in their position.
 * The episode "Not Cancer" had an incredibly obvious example, with an alleged 4-year old (who was only seen briefly) being played by a kid who was clearly, like, eleven.
 * Friday Night Lights is way guilty of this; many of the actors playing juniors and seniors in highschool are in their mid-to-late twenties.
 * The six main characters of the short-lived show Life As We Know It were all supposed to be high school sophomores (15/16), but all of their actors were 21 or 22 during filming, except for Jessica Lucas, who was 19.
 * Glee is extremely guilty of this with half of their cast being High School characters. The youngest member of the "teen" cast is 21-year old Chris Colfer with the oldest being 29-year olds Cory Monteith and Mark Salling.
 * Justified/Lampshaded with at least one member of the rival glee club, Vocal Adrenaline, who is a 24-year old "6th year senior" who has been repeatedly flunked because he's the only one who can do a particular dance move.
 * Hilarity Ensues with a recent Parents' Television Council statement on the "near pedophilia" of a recent racy GQ shoot starring Lea Michele and Diana Agron. Both were 24.
 * It's arguably justified in that every episode is a Musical Episode; it would probably be difficult too find high-school aged actors that could sing and act convincingly enough to compete with whom they've actually cast.
 * Totally averted by BBC children's dramas Byker Grove and Grange Hill, where all the actors playing children were about the same age as their characters. Some were even a year or so younger.
 * Greys Anatomy pulls off Dawson Casting with tweens: In season 1, the characters start their internship at the Seattle Grace, so they should be around 25 (give or take). Ellen Pompeo playing Meredith was 35 at the time of filming and the actors of Cristina, George and Alex were also in their thirties. Only averted with 26-year old Katherine Heigl as Izzie.
 * It's justifiable, at least in some cases- Meredith, for example, is said to have taken time off before med school, and most of the characters don't have stated ages. But it's kind of confusing when considering a character like Cristina- Sandra Oh is clearly in her 30s, so the only logical explanation is that Cristina also took time off at some point during her education, something that Cristina would never do.
 * The Channel 4 docudrama series The Queen had a mild case with the 26-year old Katie McGrath playing the 21-year old Princess Margaret (though she is 25 by the end of the episode). More extreme is the 35-year old Emilia Fox playing the 25-year old Queen Elizabeth II.
 * The same two actresses played sisters again in the BBC's Merlin, although this is arguably more Justified Trope as the Arthurian legends tend to suggest a fairly wide age gap between Morgause and Morgan le Fay/Morgana
 * That 70s Show -- Danny Masterson (Hyde), Topher Grace (Eric) and Ashton Kutcher (Kelso) were respectively 22, 20 and 20 in 1998 when the show debuted. Mila Kunis was 14, younger than her character was meant to be. However, because it ran for 8 years but was set between 1976 and 1979, she soon caught up with her character's age, then overtook it.
 * Then-18-year old Olivia Burnette was cast as a preteen Justine O'Neil in the miniseries The Thorn Birds: The Missing Years. While someone of her petite height could plausibly have passed for someone younger, her... development made it painfully obvious she was well past puberty.
 * All the older teenage characters in the HBO adaptation of Game of Thrones, such as Jon Snow, Danaerys Targaryen, Robb Stark, Sam Tarly, Theon Greyjoy, Loras Tyrell, Gendry and for Season Two . The characters are all between 16 and 20 (aged up roughly two years from the books), the actors between 20 and 29.
 * Peter Dinklage (mid 40s) playing Tyrion Lannister (early 20s) is a rather extreme example, even though the character is out of his teens. Justified Trope, as casting a dwarf in a serious drama is rather difficult. This should also become an issue as the actors who play the younger children, such as Arya Stark, who are now relatively close in age to their characters, grow up.
 * In series three of Robin Hood, 29-year old Clive Standen played 20-year old Archer and 30-year old Joanne Froggatt played Kate, whose age was never stated but it was heavily implied that she is supposed to be a young teenager.
 * In Victorious, Daniella Monet, who is 21 years old, is playing a 17 year old character.
 * German actress Josefine Preuss (b. 1986) has not visibly aged since she was about 15. Guess which roles she usually gets.
 * Twin Peaks. Keep in mind that the actors age two years, and the characters age about half a month. But at the beginning, their ages were...
 * 19-year old Lara Flynn Boyle as 17-year old Donna Hayward
 * 20-year old Mädchen Amick as 18-year old Shelly Johnson
 * 21-year old Phoebe Augustine as 17-year old Ronette Pulaski
 * 23-year old Sheryl Lee as 17-year old Laura Palmer
 * 23-year old Dana Ashbrook as 17-year old Bobby Briggs
 * 23-year old James Marshall as 17-year old James Hurley
 * 25-year old Sherilyn Fenn as 18-year old Audrey Horne
 * Mexican comedy El Chavo Del Ocho has all of its children (8 years old) characters played by adults of more than 30 years old! The result is, of course, hilarious.
 * Considering all the Amusing Injuries that the "kids" go through in the show, it'd be pretty disturbing otherwise.
 * In CSI: NY "Grounds For Deception", Stella Bonasera is revealed to have been born in 1975, making her character 35. Melina Kanakaredes who portrays Bonasera is currently 42.
 * Patrick McKenna was 31 when he started playing teen-aged Harold on The Red Green Show. Interestingly, Harold did slowly age as the series progressed, eventually going to college and getting various full-time jobs.
 * Somehow simultaneously played straight and subverted at the same time with The Inbetweeners. While the four main characters, 17-year olds, are played by actors ranging from 22 to 26, all of them look and sound the correct age. Seriously, it's creepy.
 * In Dads Army, 17-year old Frank Pike was played by Ian Lavender, who was 22 years old when the series started and 31 when it ended, while Pike had not aged.
 * Also Inverted Trope. The oldest members of the cast were Arnold Ridley (Charles Godfrey) and John Laurie (James Frazer), both into their seventies as the programme started, while 70-year old L/Cpl. Jack Jones (having served in the Mahdist War, the Boer Wars and World War One) was played by Clive Dunn, 48.
 * In the British comedy Absolutely Fabulous, 16-year old Saffron is played by 24-year old Julia Sawalha. Also somewhat inverted with her mother Edina; in an episode dealing with Edina's 40th birthday, actress (and writer) Jennifer Saunders was only 34.
 * Julia Sawalha does genuinely look 16, though. Does it fit the trope if the actor genuinely does look like a teenager?
 * When the series picked up after a break, Sawalha's age was beginning to catch up with her, and she looked closer to her real age than to Saffy's age. There is a joke, when another character looks at her passport and says she can't believe Saffy is that young, she looks older. Saffy makes a sarcastic comment with a look at her mother, that stress ages a person.
 * In Underbelly: The Golden Mile the initially 17-year old John Ibrahim is played by 25-year old Firass Dirani, although the character was 28 by the end of the series. Ironically, the show still attracted controversy by depicting Ibrahim having sex onscreen.
 * In the 1998 series Merlin-1998, Sam Neill (who was 51 when the film was released) played Merlin for about two-thirds of the first half of the film and all of the second half. However, it wasn't until the second half that Merlin would have been around that age in-story (because of the time skip necessary for Arthur to grow up). During the entire first half, he was less than half that age. The reason for this is probably because having Merlin portrayed by an actor of the appropriate age at all times would have left Sam Neil playing Merlin for only one half of the entire film.
 * In Boardwalk Empire 37 year old Stephen Graham plays Al Capone, who was 21 at the time the show is set.
 * Webster - Teenaged Emmanuel Lewis plays a seven year old.
 * Charlotte Coleman was in her early 20s when playing teenage Jess in the TV adaptation of Oranges Are Not the Only Fruit.
 * On the Soap Opera All My Children, Sarah Michelle Gellar first appeared on the show at the real-life age of 18, but she appeared as the main character Erica Kane's previously-unknown daughter. Susan Lucci, the actress who portrays Erica, has been on the show since it first aired, and there had never been a mention of an unknown daughter being born. The show tried to cover this up by claiming that the daughter was the product of a rape of Erica when she was 13, which would have made Gellar's character in her 20s. Nobody really bought it, but just wrote it off as Willing Suspension of Disbelief.
 * The CSI episode "Neverland" heavily featured three fourteen year old characters. Two were played by actual kids of that age (one from Heroes). The last was played by an actor who's 18.
 * More Selma Blair examples:
 * The Adventures of Pete and Pete almost avoided this until 23-year old Selma Blair arrived in the episode "Das Bus."
 * Amazon High with 25-year old Selma Blair as a high school student.
 * Zoe, Duncan, Jack & Jane starring 27 year old Selma Blair as high school student Zoe.
 * The American version of Kath and Kim with 36-year old Selma Blair as twenty-something Kim (though this wasn't nearly as bad as the Australian version; see below.)
 * Maddigans Quest is full of this: Jordan Metcalfe and Rose McIver were 18 and played Timon, aged 15, Garland, 14, respectively. Olivia Tennet was 14 and Zac Fox was 15 when they played 11-year olds Lilith and Eden.
 * The Hardy Boys Nancy Drew Mysteries had Parker Stevenson and Shaun Cassidy (24 and 18, when the series started filming) playing the Hardy Boys, who were supposedly 17 & 16.
 * Inverted in Disney's adaptation for The Mickey Mouse Club, in which the actors Tim Considine and Tommy Kirk were younger than the books -- 12 and 11.
 * Boston Public
 * In Seventh Heaven Barry Watson was 22 when he started playing high school junior Matt Camden, though the rest of the actors playing the Camden kids were of the right age.
 * Square Pegs is a show from the 1982/1983 season about the two groups of 14 year old freshman who vie for popularity. It is often overlooked for this trope because half of the cast is under 18 (though all older than their characters). However, the other half was over 18, including Tracy Nelson (Jennifer) who was born in 1963, Jon Caliri (Vinnie) who was born in 1960, Merritt Butrick (Slash) who was born in 1959, and Claudette Wells (LaDonna) who was born in 1954, making her 28, making her twice the age of her character.
 * Gabe Kaplan stated in interviews that he believed part of the reason the ratings for Welcome Back Kotter began to decline in series three was that the Sweathogs, whose actors were now 24-29 years old, were simply too old to still be believable as high school students.
 * Both averted and played straight in What I Like About You. Extremely averted with Holly (who's in-universe birthdays were near her actress, Amanda Bynes'); played straight with Henry, Vince, and Gary, all of whom were played by actors who were 24/25 at the time of their introductions, and Tina, whose actress was 28 at the time of her introduction.
 * Lincoln Heights has quite an extreme example with the 27-28 year old (during season 1) Erica Hubbard playing 16 year old Cassie Sutton. What makes this particularly interesting is that the actors portraying her parents where born in 1970 and 1974, making them only 9 and 5 years older than her. Even more interesting is the actors playing her younger sibling were born in 1992 and 1993, making her 13 and 14 years older than them!
 * Erica Hubbard's original birth date was thought to be January 3, 1984 which would have made her about 22-23 during season 1.
 * Kath and Kim's Kim is supposed to be in her mid-to-late 20's. Gina Riley, the actress who plays her, is pushing 50.
 * An inversion seems to have been the original four series of Upstairs, Downstairs, which covered thirty years of historical period but only four years of real time. The characters remained the same age throughout the series, frozen in time between 1903 and 1930. The only attention paid to the passage of time seemed to be James, who grew grey about the temples. In the modern remake, Jean Marsh, now forty years older, reprises her role as Rose Buck, meaning Rose ages forty years in only six between the end of the Bellamy era in 1930 and the beginning of the Holland residence at Eaton Place in 1936. It does help, however, that the cast changed periodically, with Hazel and then Virginia replacing Lady Marjorie as "her Ladyship" and the introduction of another young lady, Georgina, to take on Elizabeth Bellamy-Kirbridge's role in the story. In the servants' hall, the cast similarly gains and loses members (adding Frederick and Daisy in the 1920s), but as the series progresses we still never see Rose, Edward, Hudson, Mrs Bridges or Ruby age.
 * In the Canadian series Student Bodies, all the actors playing teenagers were in their early 20s.
 * Annie Edison on Community is in her late teens, in real life Alison Brie is in her mid-twenties.
 * Donald Glover as well, who plays Troy, who start off as 20, while he's also in his mid-twenties. The real kicker is the fact that Gillian Jacobs, who's the same age as Brie and Glover, plays a character who's close to ten years old than Troy and Annie.
 * The Beverly Hillbillies: One early episode states that Elly May is "almost eighteen". Donna Douglas was 29 at the time. Even more egregiously, her love interest in the episode, college-age Sonny Drysdale, was played by 49-year old (and looked it) Louis Nye.
 * A truly bizarre example from The West Wing. In a season four episode, Joe Quincy is being assisted by a White House Aide whom He thinks looks about fourteen and who claims to be twenty-two. She is played by Kiersten Warren who was in her late thirties and looked it. The character is never seen again aside from that scene, almost pushing it into Big Lipped Alligator Moment territory. Like one of the page quotes, Warren actually did have a child who was the same age as the character She played.
 * Gerard Campion, the star of the long-running BBC series about Billy Bunter of Greyfriars School (Bunter was in the fourth form), was 29 when he began playing the role. It lasted for close to a decade...
 * Downton Abbey starts out by doing this; for example, Lady Sybil is 16 at the time the show begins, but played by the 21-year old Jessica Brown Findlay. Since the show's time progresses considerably faster than real time, this doesn't last; by the end of season 2, Sybil has actually passed Findlay's real age.
 * When My Family began, only one of the Harper children was played by an actor close to the character's age: 13-year old Gabriel Thomson played 12-year old Michael, 21-year old Daniela Denby-Ashe played 15-year old Janey, and 27-year old Kris Marshall played 18-year old Nick. Averted towards the end of the series where Michael was seemingly the same age as Thomson, while Janey was "almost 30" and only two years younger than Denby-Ashe (thanks to Soap Opera Rapid Aging Syndrome, since the show ran for eleven years.) Marshall left after three series of the show, and has stated in interviews that the fact that he was much older than Nick made it more difficult for him to play the character.
 * In Fortysomething, Benedict Cumberbatch was about six or seven years older than university student Rory; 16-year old Edwin was played by 20-year old Joe Van Moyland.
 * In the miniseries Love, Lies and Murder, a woman is murdered and two teenage girls are involved. 24-year old Sheryl Lee plays 17-year old Patti Bailey, and 23-year old Moira Kelly plays 14-year old Cinnamon Brown.
 * In the Britcom On the Buses, Reg Varney played the role of Stan Butler, a bus driver in his late 20s, he was 53 years old when the series started.

Music

 * Alice Cooper, born in 1948, has been singing "I'm Eighteen" for over 30 years.
 * Pat Benatar, born in 1953, built an entire discography around singing about how "we are young" back in the 1980s.
 * Marilyn Manson, born in 1969, has been singing, in a first person narrative, of being a disgruntled youth, since 1994 when he was 25, though he has trouble passing for a teen no matter how much grease paint he pancakes on, or how smooth he shaves his body, and seems even more ridiculous now that he's in his 40s.
 * Madonna's early musical career centered around insinuating that she's a troubled youth, being a material "girl" who was "like a virgin" and juggling youthful crushes and youthful rebellion and wants to know "where's the party", contrasted with tougher issues such as whether or not her "daddy" would be angry that she's pregnant, and running away from home because "daddy" is abusive. She was 25 years old when she released her self-titled debut. 3 years after that, she still considering herself young enough to kiss a 13-year old in the music video for "Open Your Heart", but her critics disagreed.
 * Belinda Carlisle had a youthful-sounding voice and used it to make references about being a "kid" in "school" finding love for the first time with her band The Go-Gos. In the late 1980s, she became a solo artist to make album after album where every song was about finding love for the first time yet again, replete with air-brushed album covers to make her look like someone born after 1958.
 * Cyndi Lauper, another 30-something in the 1980s who got famous about singing about being a "girl" instead of a woman.
 * Pete Burns was 26 when he released his album "Youthquake" and the other members of British New Wave band called "Dead or Alive" were in their late 20s and early 30s.
 * Spice Girls
 * Beastie Boys
 * The Beach Boys continued to sing love songs to teenage girls even after they became middle-aged, bearded, creepy men. Not counting the unreleased track "Lazy Lizzy", in which Brian sings about stalking an underage girl, the most pedo-worthy track to appear on a Beach Boys disc was undoubtedly "Hey Little Tomboy" - made even worse by a bootlegged outtake in which the Boys seem bent on gang-raping the title character.
 * New Kids on the Block
 * Backstreet Boys
 * Indigo Girls
 * At the age of 26, Katy Perry played a 13-year-old high school student in the music video of her song "Last Friday Night (T.G.I.F.)".
 * Several of Taylor Swift's videos, such as "Fifteen" and "The Story of Us", in which she plays high schoolers. Minor examples earlier, as she wasn't that much older than her characters, but it's started getting played more and more straight as she gets older (though to her credit, she doesn't look it).

Other

 * The Virgin Mary is usually played by an actress over the age of 20, but historians say she was about 14 when she became pregnant with Jesus.

Theater

 * In most productions of Rent, the nineteen-year-old Mimi Marquez will be played by women in their 20s, most notably in The Movie, where she was played by the then 26-year-old Rosario Dawson.
 * The movie in general is a good example of this trope, with most of the original cast reprising their roles eight years after they'd created them onstage.
 * Forget Rosario Dawson - there was a New Zealand production of RENT this year. The person who played Mimi was Annie Crummer. Granted, Annie Crummer is awesome, but she's in her forties. She's more than twice the age Mimi is in the production. Good grief.
 * Likewise, sixteen-year-old Johanna in Sweeney Todd: The Demon Barber of Fleet Street gets this frequently. In the 1982 stage recording she's played by 28-year-old Betsy Joslyn. Lisa Vroman, who played her in a 2001 concert production, refuses to give her age but it's definitely well past the teen years. 20-year-old Jayne Wisener, who plays the role in the movie, is pretty close by comparison.
 * This happens with almost any teenage character in musical theatre, most notably:
 * Marius, Enjolras, Cosette, Eponine, and the students in Les Misérables. Enjolras in particular is commonly played by a man thirty years old or older, even though the character is explicitly stated in the book to be twenty-two and looks like seventeen.
 * Anne and Henrik Egerman, and Petra in Stephen Sondheim's A Little Night Music. Anne is seventeen or eighteen, Henrik is nineteen, and Petra is twenty-one. For Anne, the age-up is also to soften the squickiness of her marriage to forty-something Fredrik Egerman (though that's probably intentional).
 * And of course, Spring Awakening (both the play and musical), which features a cast of almost entirely fourteen- or fifteen-year-olds usually played by actors who are all out of high school. This is due in part mainly to the explicitly sexual nature of the material, but also to the rampant ageism... well, everywhere... which states that actual teenagers would not be competent enough to play these roles.
 * Christine and Raoul in The Phantom of the Opera, who are somewhere around twenty but often played by older actors. Inexplicably, the film Christine is played by a sixteen-year-old Emmy Rossum (with the character aged down to match) and Raoul is played by 30-year-old Patrick Wilson, even though the two are supposed to be former childhood sweethearts.
 * Matthew Broderick was twenty-one when he originated the role of fifteen-year-old Eugene Morris Jerome in Neil Simon's Brighton Beach Memoirs. Jonathan Silverman was twenty when he assumed the role for the film version.
 * This is probably pretty common with Chekhov in general, there was particularly grievous casting for The Seagull. Take for instance the 2001 production at the Joseph Papp Public Theatre, which featured 34-year-old Phillip Seymour Hoffman as 25-year-old Konstantin Trepliev, 52-year-old Meryl Streep as 43-year-old Irina Arkadina, 54-year-old Kevin Kline as thirty something Aleksei (or Boris depending on the translation) Trigorin, and 42-year-old Marcia Gay Harden as 22-year-old Masha Shamraev.
 * In the 2008 Metropolitan Opera version of Salome, the titular character, who is supposedly in her teens, is played by 48-year-old Karita Mattila, complete with momentary nudity.
 * This happens a lot in opera, mostly because the vocal maturity and training required for the music are very hard to achieve at a young age.
 * Especially jarring with "pants roles", like Cherubino from The Marriage of Figaro, where you often have a 14-year-old boy being played by a 50-year-old woman.
 * Such roles were usually written either during the hey-day of Castrato singers, or while their popularity was starting to fade. Seeing a 50-year-old woman playing a 14-year-old boy might be jarring, but seeing a 50-year-old man playing the same part and singing in a woman's register would be downright squicky.
 * Presumably all productions of You're a Good Man, Charlie Brown.
 * No presumably about it; ageist or not, children of that age haven't the ability, nor the endurance, to pull off such a long and complex show (he said, having rehearsed four children for hours on one number for a brief version that was still messed up in performance)
 * All the main characters of The Twenty Fifth Annual Putnam County Spelling Bee are around twelve years old--any theater productions of this will obviously have a cast that is much, much older.
 * In Wicked, eighteen- or nineteen-year-old Glinda and Fiyero were played by 35-year-old Kristin Chenoweth and 36-year-old Norbert Leo Butz. Then again, Kristin looks very young for her age, but not really Norbert.
 * The characters do go through a timeskip, though not nearly as large a one as in the books, so they eventually become closer to their actors ages.
 * Need we even mention Peter Pan, in which a prepubescent boy is traditionally played by a very obviously post-pubescent woman?
 * Oh, yes, you must!
 * Oh, no, you mustn't! (OK, OK, coat...)
 * How about Mr. B Natural? (Nightmare Fuel)
 * The main characters in Grease are high school students. Unless it's high school production, this trope is going to be invoked.
 * The role of eleven-year-old Iris in Morris Panych's Girl in the Goldfish Bowl was written for an actress in her mid-thirties, and is always played by an adult.
 * In Blood Brothers, you get a single actor play a character from childhood to adult, i.e. Edward at 25 is played by the same guy who plays him at 8. You get used to it.
 * In the 1996 production of A Thousand Clowns at the Roundabout Theatre in New York, Murray, a character who is supposed to be in his twenties or perhaps thirties, was played by then 61-year-old Judd Hirsch, while his older brother Arnold was played by then 59-year-old David Margulies.
 * Most high school productions of The Crucible will invoke this trope, as actors are aged 14-18, and Betty Parris is nine years old.
 * An in-universe example from Thoroughly Modern Millie. In the song "They Don't Know", the obviously past her prime Ms. Meers remarks that she could still play Juliet if the theater is big enough.
 * Theater IN GENERAL is an example of this trope: played straight or sometimes reversed
 * The three girls in Vanities are usually played by late 20 or 30-somethings. They start out as high school students at age 17, progressing through college and beyond, and by the end of The Musical they are about 40, inverting this trope to some extent. At the time of the 2009 off-Broadway run, Anneliese Van der Pol (Kathy) was 25, Lauren Kennedy (Mary) was 36, and Sarah Stiles (Joanne) was 30.
 * In the world premiere of Pilgrims Musa and Sheri in the New World, Sheri, early 20's, was played by Carol Roscoe, age 39.
 * Almost all productions of Romeo and Juliet; Juliet's supposed to be turning fourteen, but she's usually played sixteen or upwards.
 * The 2004 Off-Broadway version of bare: a pop opera had then-26-year-old John Hill, 22-year-old Michael Arden, 29-year-old Jenna Leigh Green, 26-year-old Natalie Joy Johnson and 27-year-old Aaron Lohr playing seventeen-year-old seniors.
 * Next to Normal had 26-year-old Aaron Tveit in the role of 18-year-old Gabe Goodman. Natalie, however, was played by 17-year-old Jennifer Damiano.
 * In Pokémon Live the preteen and teenaged protagonists are played by full-grown adults. It shows.

Web Comics

 * Tedd from El Goonish Shive invokes this in an EGS:NP strip by claiming to be twenty-one outside of continuity due to Comic Book Time. Grace counters the gap might be up to a year, making Tedd eighteen. She then goes on to say that it doesn't matter anyways since none of them are likely to look any different before they turn 30.

Web Original

 * This was the initial reason that some viewers suspected Lonelygirl15 to be a hoax. The Real Life implications of this are apparent in an episode of MaxterBexter, in which former lonelygirl15 actors Becki Gregoski and Maxwell Glick complain about needing to show ID before they would be served alcohol, even though Maxwell Glick was 29 at the time.
 * On the website hosting the Whateley Universe, the stories centering on Chau Lee (Bladedancer) are often illustrated with pictures of Zhang Ziyi. The character is fifteen, the actress at least twelve years older...
 * Mocked in A Very Potter Musical with CLEARLY College aged Darren Criss stating "I'm just a 12 year old kid".
 * Lucas Cruikshank was 14 when he started playing six-year-old Fred Figglehorn. Justified Trope in that he created the character to be performed by himself.
 * That Guy With The Glasses has 20-something Bhargav playing Ma-Ti, who is somewhere around 14.
 * That doesn't count because he is in show supposed to not be the real Ma-Ti and very obviously. And in any case is pretending to be a post-series Ma-Ti, hence why he's embittered over his time spent with them.
 * Even if that's the case, he still said he was fourteen when he woke up to see Marz Gurl and The Nostalgia Chick in bed with him.
 * Behind the Veil is an interesting case of this, with the "actors" being limited to celebrity representations of what the character's appearance would be. However several characters ages are either older or younger than the celebrities portraying them, for example the 32-year-old Jack Raven being represented by the 45-year-old Jeffrey Dean Morgan.

Real Life

 * In a rather Squick and creepy example, a 29 year-old named Casey Price was found posing as a 7th grader (12 years-old), fooling even the two people he was living with.
 * A woman, Treva Throneberry, pretended to be a teenager throughout her 20s and early 30s and moved from foster home to foster home. She got a tuition to go to college and was finally arrested for fraud. Interestingly, she didn't look especially youthful.
 * 31-year-old Patricia Dye posed as a teenage boy so that she could have sex with a teen girl.
 * Adult police officers will often pose as teens to catch sexual predators, or to catch juvenile offenders.
 * A member of the Hong Kong police force successfully posed as a 15-year old high school student to uncover Triad recruitment of high school students. He got the idea from a movie.
 * There was an incident where a client of a prostitution ring requested an underage girl. The owner of the ring contacted the police anonymously and agreed to help set up a sting against the client. The police sent a female officer to him claiming to be 15-years old. He believed it and discussed sexual activities with her leading to his arrest.
 * Cosplayers regularly portray characters that are considerably younger than themselves. Characters in their younger to mid-teens are prevalent in many popular series; meanwhile, the skills you need to make your own costumes require time and practice to develop. Even if you opt to buy your costumes, cosplaying eats up a LOT of money either way, so you're generally much better off if you have an income level more typical of an adult.
 * Cameron Crowe enrolled as a high school student at age 22, to research his book on teen life, called Fast Times at Ridgemont High.
 * Kevin Bacon enrolled as a high school student prior to filming Footloose just to see if he was still believable as a teen at age 25, according to the Footloose DVD commentary.
 * Riley Weston was born Kimberlee Kramer in 1966. In May 1997, she changed her name and began claiming her date of birth as 1979 in order to be considered for acting roles. The deception was assisted by her small size, with a height of 4' 11" and weight of 93 pounds. In 1998, she began drafting screenplays and marketing herself to television studios as a recent high school graduate. She was soon hired by the WB Network as a writer for the show Felicity after they saw one of her scripts about teenage sisters. Hailed as a child prodigy and "wunderkind," she was featured on Entertainment Weekly's October 1998 list of the "100 Most Creative People in Entertainment," which described her as an up-and-coming 19-year-old, though she was really 31. Shortly thereafter, she was offered a half-million dollar screenwriting deal with Disney. After Entertainment Tonight began working on a segment about Weston, her real identity and age soon emerged. Soon after, her contract with WB expired and was not renewed, and her deal with Disney fell through.
 * Barbora Škrlová was a 33-year-old Czech woman suspected with child abuse and cannibalism who fled to Norway and pretended to be a 13-year-old boy named "Adam". It worked for a while, though she was eventually arrested and sent back to the Czech Republic.
 * When Shirley Temple was signed with Fox Studios (later part of Twentieth Century Fox), the studio shaved a year off her age to make her seem more precocious, even altering her birth certificate. She was initially presented to the public as a four-year-old when she was actually almost six. Shirley didn't learn how old she really was until she was thirteen.
 * Community colleges tend to have students that look well above the age of a typical college student
 * Similar to the Shirley Temple example above, Gypsy Rose Lee and her sister June Havoc had years shaved off their ages when they performed as child stars. Their mother, the legendary Stage Mom Rose Hovick, reportedly had many fake birth certificates for them and they couldn't be sure of their real ages.

Film

 * Michelle Trachtenberg was in her late teens playing 18 year old Jenny in Eurotrip.
 * She played the 11-year-old sixth-grader Harriet in Harriet the Spy, while the actress was 10 years old to the day when shooting began on October 11th, 1995 (this may have been done for labor law reasons, or it may have been a coincidence).
 * She went on to play the 17-year-old lead in Ice Princess, filmed when she was 18. Her co-star Hayden Panettiere, whose character is around the same age as Michelle's (they're in the same grade at school), was 14 at the time.
 * Daniel Radcliffe, Rupert Grint, and Emma Watson were all the same age as their characters in Harry Potter when they began the film series at age 11. Of course, as time has gone on, the actors have gained a bit of a lead on the characters they play, to the point that, as of Harry Potter and the Deathly Hallows, they're all 20-21 years old but playing 17-18 year-olds.
 * Emma Watson actually started off younger than Hermione. In the first film, she was 10-years-old playing 11.
 * This was the subject of a misaimed parody in Epic Movie, where the "kids" were all in their forties, and "Hermione" was nine months pregnant. It gets even more inappropriate: "Hermione" was shown smoking.
 * The title role in Babe was played by 48 different piglets, because they grow so quickly. A makeup artist was employed to make the pigs look similar.
 * All the lead actors of Ten Things I Hate About You were actual teenagers: 19-year-old Heath Ledger and 17-year-old Julia Stiles, Joseph Gordon-Levitt and Larisa Oleynik (though the latter two play fifteen-year-olds).
 * Lindsay Lohan is the same age as her characters in her early films, particularly Freaky Friday and Mean Girls.
 * Sue Lyon was 14, and playing 14, when she filmed Lolita. (In the original novel, Lolita was 12; the character's age was raised to comply with the censors. Nabokov himself had said "to make a real 12-year-old girl play such a part in public would be sinful and immoral.") Many are under the mistaken impression that she was 16, because the film was released in 1962, and Lyon was born in 1946. The film was, however, filmed between November 1960-May 1961, and she was born July 10th, 1946, making her 14 for the duration of filming.
 * Similarly, Dominique Swain was 15 when she played the 14-year-old Lolita in The Remake (again, the character's age was raised to comply with the censors).
 * The 10-year-old (at time of filming) Fairuza Balk played the older but still preteen Dorothy Gale in Return to Oz.
 * Michael Cera (Evan) was 18 and Christopher Mintz-Plasse (Fogel/"McLovin") 17 when playing their graduating high-school characters in Superbad. Jonah Hill (Seth), by contrast, was 23 (due to legal regulations, Mintz-Plasse's mother actually had to be on the set of Superbad the day his character's sex scene was shot).
 * The 1968 Franco Zeffirelli film of Romeo and Juliet featured one of the only examples of an actress playing Juliet being anywhere near her age. Juliet, who is supposed to be nearing 14, was played by 15-year-old Olivia Hussey. Hussey was famously barred from the premiere due to her age. In effect, she was deemed too young to witness a scene featuring her own nude body. Seventeen-year-old Leonard Whiting was impressively young for Romeo, as well.
 * Gogo Yubari, the psychotic 17-year-old killer from Kill Bill was played by the 18-year-old Chiaki Kuriyama (the film was released on her 19th birthday).
 * Leonardo DiCaprio was twenty-two when he played twenty-year-old Jack Dawson in Titanic.
 * Inverted in Mysterious Skin with Brady Corbet and Michelle Trachtenberg. Corbet was 15 and playing a 17-18 year-old, while Trachtenberg was 18, the same age as her character.
 * The Star Wars films. Carrie Fisher was 18 when playing 19-year-old Princess Leia (and then 21 when playing 22-year-old Leia in The Empire Strikes Back, and 24 when playing 23-year-old Leia in Return of the Jedi). 19-year-old Anakin Skywalker was played by 19-year-old Hayden Christensen at the time of filming Attack of the Clones; when Anakin was 22, in Revenge of the Sith, Christensen was 22. Natalie Portman was 16 when playing Amidala at 14; she also played her at 24 when she was 19, and at 27 when she was 22.
 * Pans Labyrinth. Guillermo del Toro changed the screenplay when he was impressed by an actress a few years older than the part asked for initially.
 * Kirsten Dunst was eleven years old in Interview with the Vampire, where she played a vampire who was infected at eleven years old and was never able to grow up. Her kiss with the adult Brad Pitt led to a fair amount of controversy.
 * Interestingly (according to an interview with Dunst shortly after filming), the director called cut before they actually kissed on almost all takes (you'll notice she has her hand between the camera and their mouths when she leans in for the kiss, presumably to cover this) but there was one time when cut wasn't called early enough. Dunst was not pleased about this.
 * The book version of Claudia (Dunst's character) is assumed to be between three and six years old at the time of her turning. The character was likely aged up for the movie because the filmmakers would have had difficulty casting such a young child into the role.
 * The Virgin Suicides: The actresses playing the younger Lisbon sisters were close in age to their characters, from Kirsten Dunst (16) as 14-15 year-old Lux, to Hanna R. Hall (14) who played 13-year-old Cecilia, to Chelse Swain (15) as 15-16-year-old Bonnie.
 * Lost in Translation: Scarlett Johansson was not yet 18 when she played Charlotte, who is in her early-to-mid twenties (going by her reference to having graduated from college a little while previously). Johansson had just graduated from high school when she got the part.
 * In Somewhere, 11-year-old Cleo is played by 11-year-old Elle Fanning (she was 12 by the time of its release).
 * Yet another Sofia Coppola film, Marie Antoinette, features a partial subversion - it starts off playing the trope straight by having 23-year-old Kirsten Dunst portray the future queen of France at age 14, but Dunst continues to play her all the way into her thirties.
 * The Film of the Book Twilight: Kristen Stewart (Bella) was actually seventeen and Taylor Lautner (Jacob) was fifteen during filming. Robert Pattinson is twenty-two, in contrast to the eternally 17-year-old Edward. The rest of the actors playing the Cullens are mostly in their early twenties, but it's justified as their characters aren't even really of high school attending age to begin with.
 * Chloë Moretz, at 11, plays 10-year-old Hit Girl in Kick-Ass. 17-year-old Kick-Ass himself is played by 19-year-old Aaron Johnson.
 * Matchstick Men is an unusual case in that an actress in her twenties plays a 14 year old girl with surprising believability, yet
 * In Apocalypse Now, Laurence Fishburne played a 17-year-old soldier, but he was only 14 years old when filming started (due to the film's long period of production and post-production, Fishburne was 17 when the movie was released).
 * In Sixteen Candles the 16-year-old protagonist is portrayed by a 16-year-old Molly Ringwald. In the same movie, the trope is delightfully lampshaded by Ringwald's comments on a classmate (played by then-25-year-old Haviland Morris). "I swear to God, Caroline Mulford had to flunk about nine grades."
 * In Pretty in Pink, Molly Ringwald was 18 while playing a high school senior.
 * In the movie Real Genius, Gabe Jarret played a 15-year-old, and was actually 15 at the time of the film's release.
 * Averted Trope in Danny Boyle's 2008 film Slumdog Millionaire: eighteen-year-old Dev Patel plays eighteen-year-old Jamal Malik.
 * Partial subversion: In the film version of Bernhard Schlink's The Reader, eighteen-year-old David Kross plays main character Michael Berg from the age of fifteen into his early twenties. Considering the fairly explicit sex scenes with co-star Kate Winslet, there was very little chance of Michael being cast any younger. It is also worth noting that, although this is not mentioned in the film, the book features a brief scene in which Kate Winslet's character Hanna Schmitz expresses the false understanding that Michael is at university already when she starts having sex with him, implying that he looks several years older than he actually is.
 * In Monty Pythons the Meaning of Life there is a scene in which an instructor (played by John Cleese) at what appears to be a religious institution of learning is teaching a class how to have intercourse with his good lady-wife. While in the church service, all the children are... well, children. When we get to the classroom and intercourse discussion, however, they are all played by the various Pythons.
 * When the instructor catches one of them playing with an ocarina, he punishes him by making him play on the rugby team later, which is made up of actual children again!
 * Mia Sara was perhaps the only actual teenager in Ferris Buellers Day Off. Her character Sloane was a junior in high school; she was 18 at the time.
 * The Professional features a thirteen-year-old Natalie Portman playing twelve-year-old Mathilda. Which makes her love towards Leon as poignant as it's odd.
 * In To Have And Have Not, Lauren Bacall was 19 and playing a 22-year-old.
 * Evan Rachel Wood was fourteen when she was cast in Thirteen, the title referring to her character's age (Wood turned fifteen during filming). Considering the sex-and-drugs subject matter of the movie, probably no one would have blamed them if they had cast a baby-faced adult, so it's a notable near-aversion.
 * Tara Steele was about ten when she played teenaged Katie in Mockingbird Don't Sing, though the character was 'supposed' to look much younger than she really was.
 * Anton Yelchin was eighteen when he played the titular Charlie Bartlett.
 * Rebel Without a Cause is a partial exception; Natalie Wood and Sal Mineo were 16, portraying teens. James Dean, however, was 24.
 * Victoire Thivisol was four years old when she played the main role in Ponette, that of a four-year-old who loses her mother. She even won a Volpi Cup for Best Actress at the 1996 Venice Film Festival for her heartbreaking performance.
 * All of the teenagers in Casper were played by people between the ages of 13 and 15 (including the voice actor for the titular character), and the is played by a 17 year old. For somebody used to Dawson Casting in movies, the sight of an entire classroom of teenagers who actually look like teenagers is actually rather jarring.
 * The live action adaptation of The Last Airbender both plays this straight and subverts it. Jackson Rathbone (Sokka) was 25 playing 15 and Dev Patel (Zuko) was 19 playing 16, but both Noah Ringer (Aang) and Nicola Peltz (Katara)were the same age as their characters during filming (12 and 14 respectively).
 * Disturbingly avoided in Taxi Driver. Jodie Foster was 13 when she played the role of a 12-year-old prostitute (except for the nude scenes, which were performed by her older sister, who was of legal age).
 * The Sound of Music largely kept the actors relatively close to their ages - Nicholas Hammond (Friedrich) was fifteen playing fourteen, Heather Menzies (Louisa) fourteen playing thirteen, Duane Chase (Kurt) thirteen playing eleven, Angela Cartwright (Brigitta) twelve playing ten, Debbie Turner (Marta) eight playing seven, and Kym Karath (Gretl) six playing five. Played utterly straight, however, with Charmian Carr (Liesl), who was twenty-one playing sixteen-going-on-seventeen.
 * In Another Cinderella Story, Selena Gomez was 15 and playing a 15-year-old high schooler. Critics were squicked that Drew Seeley, who played her love interest, was 24, but the movie makes it clear that his character really is that age.
 * A Cinderella Story also averts this with Hilary Duff (whose character is 17 - she was 16 when the film was released).
 * The Diary of a Wimpy Kid film adaptation. The supplemental film diary mentioned that a lot of the child actors used were actual middle-schoolers and that the two boys playing Greg and Rowley actually missed their first days of sixth grade to film the movie.
 * Borderline case: Most of the actors playing students in Skyhigh were between 17 and 19 at the time of the film's release, although many of them played high school freshmen.
 * In the 2010 version of True Grit, then 13 year old Hailee Steinfeld played 14 year old Mattie Ross.
 * Brooke Shields, in her 1980s movie appearances from Age 14-17 (most famously The Blue Lagoon), appeared in a variety of R-rated films that involved frontal nudity. In each case, an over-20 body double covered those moments for her.
 * Mandy Moore was 18 when she played high school student Jamie in A Walk to Remember, though her also high school aged love interest was played by Shane West, who was 21 at the time.
 * Walking the line in Mystery Team; the actors are in their early twenties, and their characters are high school seniors.
 * Ann Miller played a character several years older in You Can't Take It With You when she was fifteen.
 * In Welcome to The Dollhouse, released in 1995, Heather Matarazzo, born in 1982, is the right age to play a seventh grader.
 * While a number of the cast members who play tributes in The Hunger Games are borderline cases, it's definitely averted by Isabelle Fuhrman (Clove), Jacqueline Emerson (Foxface) and Amandla Stenberg (Rue) - aged 15, 17 and 13 respectively at the time of release.

Live-Action TV

 * Claire Danes (Angela) and Devon Gummersall (Brian) from My So-Called Life really were teenagers at the time of filming -- although the rest of the teenage characters were played by twentysomethings (including the aforementioned Senta Moses).
 * This is a rare, possibly unique inversion, especially for an actress, as the producers knew that Danes was only 13 years old (at the start of filming) yet they still cast her to play a character two full years older than the actress, without any retcons or fudging the numbers.
 * Justified with Jared Leto in the character of Jordan, who is repeating the grade the rest of the kids are in...at least for the second time.
 * The teens on Degrassi are all played by real teens -- but they're much more attractive than the typical bunch of high schoolers (see Hollywood Homely).
 * The show has been slipping into example of this, but only due to a change in season coverage. Early seasons went at an equal time (1 school year per season), since season six ended they now run the series at half the speed (half a school year per season). This means that members of the cast are now older than their characters. However, most new characters are still about the same as their actors when introduced, leaving it well short of being as bad as The Trope Namer or any other example.
 * Beverly Hills, 90210 did manage to avoid Dawson Casting in a few cases: Shannen Doherty (19) and Jennie Garth (18) were borderline, but at least they were still teenagers. Brian Austin Green and Tori Spelling, both 17, were clear aversions. Douglas Emerson, who played Scott Scanlon, was actually 16, making him the only actor the same age as his character, but he was written off in the second season.
 * Most of the original cast on Saved by the Bell were close to age-correct, though there was a little leakage into the 20s by graduation from the portion of the cast not from the original Good Morning Miss Bliss:
 * Mark-Paul Gosselaar, who played Zack, was 14 when he started on Good Morning Miss Bliss, playing an eighth-grader and was 19 at "graduation". Lark Voorhies, who played Lisa, was only a few weeks younger than Gosselaar. Dustin Diamond was three years younger than them, and the youngest in the cast, playing an eighth-grader at age 11 (and a high schooler at 12). If you were wondering why it took so long for Screech's voice to drop, that's why.
 * The two kids from Good Morning Miss Bliss who did not carry over to Saved By The Bell, Max Battimo and Heather Hopper, were 14 and 12 respectively.
 * Mario Lopez (Slater) started out at age 16, graduating at 20; Tiffani(-Amber) Thiessen started at 15, making her the same age as Gosselaar and Voorhees. The eldest was Elizabeth Berkley, 17 when she started and 21 when it ended.
 * The other kids on Hannah Montana, including star Miley Cyrus, were actually in their early-to-mid-teens when the show started, making the casting of Jackson all the more glaring - and baffling.
 * In general, Disney Channel is pretty good at averting this trope.
 * Averted in Shake It Up, where the characters are supposed to be in high school. In fact, leads Bella Thorne (Cece) and Adam Irigoyen (Deuce) were only 13 years old playing high school freshmen at the start of the series.
 * Super Sentai often averts the trope: post-2000 series rarely feature main cast members older than 22-23 maximum, save for some Sixth Rangers who were older than the main heroes. Several recent series have had 15 to 17-year-old characters played by actors of the same age and even teenagers playing characters older than themselves - Shinkenger has 14-year-old Runa Natsui as 17-year-old Kaoru. There are however a few examples of the trope played straight, such as Goseiger where 20-year-old Mikiho Niwa plays 17-year-old Moune.
 * In Tokumei Sentai Gobusters, Ryuji is played at 28 years old by Ryouma Baba (who turned 27 soon after the start of filming) and at 15 years old by Koudai Matsuoka (a year younger than the character.)
 * Possibly the most hilariously exaggerated inversion yet -- in Hikonin Sentai Akibaranger, 23-year-old Yumeria Moegi is played by 16-year-old Karin Ogino.
 * Christina Applegate was 15 years old and playing a 15-year-old in the first season of Married With Children (her character's age was said to be 16 a few months before Christina herself, making it a rare case of a teen actor younger than her role).
 * David Faustino was much the same, playing a 12-year-old boy when he was in fact 12 years old. In both cases, the characters aged at the same rate as the actors. Of course, while Kelly was repeatedly stated to have an active sex life, Applegate wasn't actively portrayed making out on camera until after she turned 18.
 * The Bill features a 19-year-old character, played by an actress who was 17 when she started filming.
 * Sarah Michelle Gellar was 16 when she started playing Erica Kane's long lost daughter Kendall Hart on All My Children, who was in her twenties. It should be said though that her character's age was a Retcon from 16 because of the continuity errors it created.
 * Freaks and Geeks had a good percentage of its cast close to or of the high school age (24-year-old Linda Cardellini and 21-year-old James Franco being exceptions). John Francis Daley, playing a very small and scrawny 14-year-old, was the same age as his character.
 * Also, in Bones, in which a now 24-year-old John Francis Daley plays 24-year-old wunderkind psychologist Lance Sweets.
 * In Battlestar Galactica Reimagined, Kara "Starbuck" Thrace is about 28-29 years old by the end of the third season, going by a reference to her having graduated from the military academy six years previously. Katee Sackhoff, the actress who played Kara, was only 26 at the time.
 * For that matter, the fact that she was cast could be considered an inversion of this trope: the original script for the miniseries described Starbuck as being in her thirties. Katee was 22 when she tried out for the part and eventually got it, despite initial objections from the casting directors that she was too young.
 * Firefly has twenty-year-old Jewel Staite playing Kaylee, who is implied to be older than 17-year-old River (played by Summer Glau, who IRL was a year older than Jewel).
 * There's also a 27-year-old Sean Maher playing Simon, who's around 25, going by the age of the child actor who portrayed a young Simon.
 * And a brief look at Mal's ID shows us that he's 49, despite the fact that Nathan Fillion was only 31 when the show went on air. Fans are still divided over whether this means people in the future age really slowly, or someone just got the last two digits of Mal's year of birth mixed up.
 * F Troop's "Wrangler Jane", presumably a character in her twenties, was played by Melody Patterson. Melody got the part after lying about her age initially, and was only 15 years old at the start of the show.
 * On That 70s Show, the 15-year-old character of Jackie Burkhart was played by the actually 15-year-old Mila Kunis. Mila lied about her age to be allowed to play the character. Thus, she was 14 when they started filming the series, but the producers thought she was 16.
 * The story goes that when asked how old she was, Mila said, "I'll be 18 on my birthday." She just didn't say which birthday. The producers liked her so much that they decided to keep her even when they found out the truth.
 * When the show started, Laura Prepon and Wilmer Valderrama were also teens; however, they aged normally, while their characters did not.
 * In Supernatural, Jared Padalecki and Jensen Ackles are actually almost exactly the same ages as their characters, Sam and Dean Winchester. They are each one year older than their characters, but the four-year age gap between them is the same.
 * However, Jeffrey Dean Morgan, who plays their father, is only 12 years older than Ackles (something Padalecki and Ackles used to tease him about). This begins to border on squick for those who also watch Grey's Anatomy, considering Jensen Ackles (his son) and Katherine Heigl (his girlfriend) are the same age.
 * Played straight with Teen!Dean in "After School Special," but inverted with Teen!Sam: the actor playing 14-year-old Sam played 8-year-old in "A Very Supernatural Christmas" a year before. The kid was about 12 years old or maybe 13, but very small for his age.
 * The cast of Skins are generally the same age as the characters they play; given the show's apparent policy of "sex, drugs, and nudity whenever possible," one does wonder how many over-18 viewers have wound up feeling really conflicted or really dirty at some points.
 * Not many, since the age of consent in the United Kingdom is 16.
 * The American version landed in hot water with the Moral Guardians for casting teenaged actors. Most notably, a nude scene was shot involving a 17-year-old actor... and then the producers realized that it was child porn.
 * Gilmore Girls featured 33-year-old Lauren Graham as 32-year-old Lorelai Gilmore, and 18-year-old (at the time of casting) Alexis Bledel as 16-year-old Rory Gilmore.
 * Lucy Griffiths, who played Marian in the BBC's 2006 version of Robin Hood was 18 and playing a 21-year-old character in the first series.
 * On The Wire, Jermaine Crawford (Duquan "Dukie" Weems), Maestro Harrell (Randy Wagstaff) and Michael B. Jordan (Wallace) were the same ages as their characters (15, 14, and 16 respectively).
 * Many Nickelodeon shows using a live-action cast actually used actors around the same age as their characters.
 * Notably, The Adventures of Pete and Pete actually paid attention to how old the characters were and raised their ages accordingly and the producers later commented that the kids essentially grew up on the set because they'd been doing the shorts and television series for so long.
 * Drake and Josh had the title actors be the appropriate age, with Miranda Cosgrove playing a 10-year-old. But the show's timeline was different then real time, and the actors were hitting their 20s when the characters were still in High School. Cosgrove especially was about 14, still supposedly about 11 or 12.
 * Melissa Joan Hart was fifteen when she started playing Clarissa Darling, and her character aged up accordingly.
 * Claire in Heroes was 17 years old - and played by 16-year-old (when the series started) Hayden Panettiere - until the writers noticed fans enjoying the chemistry displayed between Claire and 26-year-old Peter and writers docked her age down one or two years to make them less comfortable with the pairing until The Reveal of
 * The kids who play Molly Walker and Micah Sanders are about the same age as their characters, or at least they were until the show took some time off. Micah is supposed to be eleven, and the actor is now fourteen, which is very noticeable as puberty has begun to kick in and his voice changed. Deepest voice on an eleven year old ever.
 * In Home Improvement the actors playing the kids were all of appropriate age: Zachary Ty Bryan (Brad) was the same age as his character, Jonathan Taylor Thomas (Randy) was a year older than his character and Taran Noah Smith (Mark) was a year older than his character.
 * Arrested Development had Michael Cera and Alia Shawkat at almost the exact age of 14-15.
 * Of course, now The Movie is in the works, so one wonders if this will slip into the non-exception category (Cera is 21 and Shawkat is 20 right now).
 * Tyler James Williams, the young Chris Rock on Everybody Hates Chris, was 12 when he began playing his middle-school-aged role. Unfortunately, he's since hit puberty ... and now his voice is noticeably more baritone than that of the adult Chris Rock, who narrates the show.
 * Not to mention one of the early jokes of the show was that Chris' younger brother was taller than him (mirroring Chris Rock's real life younger brother who grew taller than him at an early age). After puberty, Williams was much taller than the other actor, not to mention his constant bully (though the bully remained much bulkier than the skinny Williams).
 * Holly Tyler of What I Like About You was exactly the same age as her portrayer Amanda Bynes (starting at 16 in the pilot), AND aged in real time to boot (both were nearly 20 in the finale).
 * In What a Girl Wants, Bynes was a sixteen-year-old playing a seventeen-year-old.
 * Neil Patrick Harris was more or less the same age as his character when he was in Doogie Howser, M.D., although the show does illustrate why Dawson Casting exists -- he really grew from season one to season two.
 * Harris was in fact, the same age as Doogie. He was only about 3 months older than his character.
 * However, Max Casella was 22 years-old when he began playing 16-year-old Vinnie.
 * Most of the Boy Meets World cast (with the already-mentioned exception of Trina McGee) were fairly close to the ages of the characters they portrayed. In the first season, Will Friedle was 17 and playing a 15-year-old and 11-year-olds Cory, Shawn, and Topanga were portrayed by Ben Savage (13), Rider Strong (13), and Danielle Fishel (12). But the timeline actually moves faster in the BMW universe than in real life: The gang takes five years to graduate high school instead of seven, making Savage and Strong the same ages as their characters (and Fishel a year younger). Matthew Lawrence joined the cast in the fifth season at age 17, playing Shawn's older brother, despite being two months younger than Strong.
 * In fact, even though only two years of college are shown, it is strongly implied that at least three years have passed; Eric, Jack, and Rachel are all graduating despite (apparently) being Juniors. This makes Maitland Ward, who joined in the sixth season at age 21, yet another aversion.
 * The reason Dawson Casting exists was perfectly demonstrated in the episode "Better than the Average Cory", where we meet 13-year-old artist Alexandra Nechita (playing herself), who strikes up a friendship with Cory's little sister Morgan, who is the same age (and played by also 13-year-old Lindsay Ridgeway). Nechita looks several years older than Ridgeway, to the point that one reviewer could not believe they were the same age, even though they were.
 * Willa Holland really was fourteen when she played fourteen-year-old Kaitlin Cooper on The OC. Actually, she didn't turn fourteen until just after her first episode aired, but that's fine because Kaitlin was eleven two seasons earlier, anyway.
 * Mischa Barton was 17 when Marissa was 16 in the first season.
 * Malcolm in the Middle cuts this fairly close; 15-year-old Frankie Muniz played 14-year-old (at the start) Malcolm; 9-year-old Erik Per Sullivan played his younger brother Dewey; 20-year-old Christopher Masterson played his graduated and world-hopping brother Francis; but his older brother Reese was played by 14-year-old Justin Berfield (who was taller than Frankie, and remained so throughout the entire series, to the producers' probable relief).
 * At least later on. At first, Francis was 15 and at military school, and the younger three brothers were in elementary school. But then the producers had to tweak things when the teen actors couldn't maintain the appearance of being pre-teen.
 * Invoked in one episode, an adult woman in her early 20s poses as a student in order to bust drug dealers. Nobody is fooled.
 * Growing Pains had their Cousin Oliver characters played by actors around their ages. By the final season in 1991, Ashley Johnson was eight, playing the suddenly six-year-old Chrissy Seaver. Luke Brower was fifteen years old, played by sixteen-year-old Leonardo DiCaprio.
 * Matthew in One Life to Live is canonically about a year older than actor Eddie Alderson.
 * Richard Castle's daughter Alexis is fifteen, as is her actress Molly Quinn.
 * The whole Castle family falls under this trope. The actors portraying Richard Castle and his mother (Nathan Fillion and Susan Sullivan) were 37 and 66 when filming began. That makes Castle a young father, but it does work out.
 * Lie to Me: Cal Lightman's daughter is 15/16; the actress playing her 18.
 * Although the flagship character of Caprica (Zoe Graystone) is played by someone about six years older than the character, Tamara is herself a semi-exception. Genevieve Buechner is older than Tamara Adama but she's much closer than her colleagues to her character's age, being only 18 while her character is about 15.
 * A deleted scene from the Pilot of The X-Files shows Scully as a teacher at Quantico, and it has been noted by many fans that she looks much younger than her students.
 * Gillian Anderson was actually four full years younger than her character on The X-Files. She lied to the producers of the show to say she was 27, to make her seem more credible as an FBI agent with a medical degree.
 * David Duchovny was only a year older than his character, Mulder.
 * New Zealand series The Tribe averted this with every one of the actors playing characters the same age, give or take a year.
 * The Canadian TV series Ramona, based on the Ramona Quimby books, subverted this surprisingly well. Ramona is 8 years old and in third grade. So is her actress. (The film, on the other hand, is a ludicrous example of this trope played very straight!)
 * Breaking Bad's high school-age Walter White, Jr. is played by high school-age RJ Mitte. As of Season 3, both character and actor are 17.
 * The George Lopez Show averts this with Max, who is played by Luis Armand Garcia. They are both the same age. Played somewhat straight with Carmen (Masiela Lusha), in that Masiela Lusha was 17 at the start of the show and Carmen was supposed to be 13-14.
 * All characters on The Wonder Years had ages to match their roles, with star Fred Savage being 11 years old when the show first began. Following this trope, Fred Savage has had trouble finding work as an adult after his lauded childhood acting career.
 * Pretty Little Liars averts this with Sasha Pieterse who began playing the role of Alison DiLaurentis at age 14, one year younger than the character. As The Other Wiki puts it, "being only 14 at the time, she is the youngest actress on the show, all her co-stars being in their late teens to early 20s."
 * Averted in Earth 2. 8 year old Uly Adair and 10 year old True Danziger were played by actors aged 8 and 10 respectively.
 * The kids on Full House
 * Unlike almost all of her costars, Michelle Trachtenberg in Buffy the Vampire Slayer was the same age as her character, Dawn (14 years old when she first appeared on the show).
 * Another aversion: at the time of Faith's first appearance in Faith, Hope and Trick, Eliza Dushku was actually seventeen, Faith's age at the time (she had to apply for legal emancipation so she could work on the show unencumbered by child labour laws).
 * Skins has mostly averted this trope. As a rule, most of its main characters aged 16-18 have been played by actors that same age or a tiny bit older, 20 at the most. However, Series 6's guest character Poppy Champion was meant to be 13 but was played by 19 year-old Holly Earl, who was therefore older than a lot of the main cast (but was arguably more convincing in her downplayed age than many examples of this trope), including Alo who she had a storyline with involving him having sex with her unaware of her age, dumping her instantly when he finds out, then being accused of paedophilia when she reports him out of anger.
 * Taylor Momsen was fourteen when Gossip Girl premiered, same age as her character Jenny. This ended up pulling the plug on the planned Jenny/Nate romance in season two since Chace Crawford (in his twenties) wasn't comfortable with a storyline that would have him regularly making out with a then fifteen year-old.
 * Most of the actors and actresses playing kids on The Secret World of Alex Mack were within a few years of their characters' ages.
 * In Young Blades, 16-year-old Robert Sheehan plays the nearly 16-year-old King Louis XIV.
 * In The Sarah Jane Adventures, Luke Smith and Maria Jackson were played by actual teenagers. This demonstrates one of the advantages of Dawson Casting because both actors had to leave the show for academic reasons.
 * Inverted on The West Wing. Elizabeth Moss is at least a year younger than Zoey Bartlet.
 * On 3rd Rock from the Sun, Tommy was Really Seven Hundred Years Old, but his fake Earth age was always the same as Joseph Gordon-Levitt's real age (both were fourteen in the first season). Both his girlfriends were played by actresses (Shay Astar and Larisa Oleynik) born in the same year as him. However, there was the interesting situation of Joseph Gordon-Levitt looking younger than he actually was, especially in the early seasons. August looked like she was a good year or two older than Tommy, but actually Shay Astar is seven months younger than Joseph Gordon-Levitt.
 * On South of Nowhere Chris Hunter was 18 at the time of filming playing the 17-18 year old Glenn. It's notable because he was three years younger than the actress playing his younger sister.
 * In the Made for TV Movie Birds Of Prey David Janssen plays an ex-WWII pilot who now flies a traffic helicopter. The film was made when Janssen was 41, and he was 14 when the war ended!

Theater

 * John Owen Jones was 26 when he first assumed the role of Jean Valjean in Les Misérables, who ages from late thirties-early forties at the beginning of the show and into his sixties by the end. Alexander Gemignani was 27 when he starred as Valjean in the Broadway revival. This kind of thing also happens to a lesser degree with Javert and the Thenardiers, who age similarly to Valjean throughout the show, and are usually cast near the younger end of that range (i.e. 40s). Valjean, however, is most susceptible to inverted Dawson Casting due to the role being written for a high tenor, and there are few men Valjean's age who can hit those high notes with the kind of power necessary for the role.
 * Similarly, this has been a respected convention for the casting of the very aged King Lear, due to the exhausting nature of the role (in one scene, Lear has to carry around ). However, this has not stopped many of the Shakespearean actors in their sixties and seventies from taking on the role, particularly more recently, and often multiple times throughout their lives. As a result, Lears come in all different ages.
 * Sir Laurence Olivier at 39, then again at 75.
 * David Warner at 64.
 * James Earl Jones at 43.
 * Sir Donald Wolfit throughout his (and the) 50s.
 * Orson Welles at 38, then again at 43.
 * Lee J. Cobb at 57.
 * Sir Ian Holm at 67.
 * Sir Ian McKellen at 68.
 * William Devlin at 49.
 * Christopher Plummer at 66.
 * Stacey Keach at 64.
 * Sir Michael Hordern at 59, 64, and 71.
 * Kevin Kline at 60.
 * Nonso Anozie at 22.
 * Sir John Gielgud at 26, 46, 51, and finally at 90(!), as part of an all-star radio production.
 * Both Thirteen and the recent revival of Bye Bye Birdie averted this, casting real teens to play the teen characters.
 * Ditto for certain stage productions of High School Musical, notably those by real high school theatre departments.
 * Amy Nuttall was 16 when playing Christine in The Phantom of the Opera on the West End, and to date is the youngest leading actress ever featured in the London production.

Other

 * Incredibly, Maria Callas began her opera career at the age of 15, as the leading lady in Cavallera rusticana, which is about a young, knocked-up village girl, probably about 15-16. Since it requires performers who can sing over an orchestra, this trope doesn't have many opera exceptions, folks.
 * Although there is one other noticeable aversion in the field of opera -- Tchaikovsky's opera Eugene Onegin. Tchaikovsky felt that older singers playing young, passionate lovers would cause people to be unable to take his opera seriously. He had students at the Moscow Conservatory put on the first performance of Eugene Onegin.
 * Lampshaded by the Firesign Theatre on their album Don't Crush That Dwarf, Hand Me The Pliers; High school student Porgie Tirebiter's best friend Mudhead is in court, and the prosecutor (Porgie's dad) says "So you don't go to school?" to which Mudhead replies, "Hell, no! I'm thirty years old!"
 * This one is in "Other" because it derives from Theatre, Live-Action Film, and Television: Patty Duke in three separate productions of The Miracle Worker. Duke was able to play Helen Keller on Broadway well into her teens, and played her again in the 1962 film adaptation, partly because she was very small: even in adulthood she has never grown taller than five feet. Her height presented a particular challenge to the producers of the 1979 TV remake, in which she played Annie Sullivan, because she was cast opposite fifteen-year-old Melissa Gilbert -- confronting audiences with a seven-year-old Helen Keller who was taller than her teacher.
 * The Full Cast Audio book recordings, which was founded by Bruce Coville, always uses age-appropriate voice actors for every book they record.
 * In the notorious "Friday" video, 13-year-old Rebecca Black and her real-life friends (who are presumably in the 12-14 range) play characters who are at least 16, as one of them is driving a car. This has been observed and lampshaded in many parodies.
 * In the music video for Aerosmith's song "Crazy", 17-year old Alicia Silverstone and 16-year old Liv Tyler play two students who skip class and go on a road trip together. The fact that this is an exception is surprising because the video is Fan Service-heavy and even features Liv doing a striptease at one point. Not to mention the fact that Liv is lead singer Steven Tyler's daughter.

Real Life

 * School plays and musicals usually invert or avert this.
 * Traci Lords did adult entertainment when she was a minor. She did (and does) look older than most people who were born in 1968. When the feds tried to bust the smut peddlers for molesting innocent Traci, the case fell apart when the government admitted that it, too, had been fooled when Lords traveled to Europe on a fake passport.