Real Life Relative

When two or more characters in a show have some form of real-life relationship, be it familial or romantic, off-screen. Extra points if the relationship is replicated on-screen. It can make love scenes more convincing if the two people involved are regularly having a candlelit dinner or giving the trailer's springs a workout. For blood relatives, the family resemblance can do wonders for convincing the audience that these people are family. In some instances, however, real couples may have no onscreen chemistry.

Can lead to some very interesting scenarios, including Actor Allusions, or may lead to more Reality Subtext issues than the production was actually looking for. (In films, this element can often be played up by the promotional machine.) For a more Squick version there is Cast Incest where the actors of characters who are blood related go out in real life.

It is also not unheard for a couple to be on opposite sides of an on-screen divide, making for some interesting Foe Yay scenes.

Compare I Want You to Meet An Old Friend of Mine, Couple Bomb and Actor Allusion. For cases where actors start a real-life relationship after being cast as characters with an on-screen relationship, see Romance on the Set.

Anime and Manga

 * Occasionally happens in FUNimation dubs. Jessica Dismuke played Yukina in Yu Yu Hakusho, while her brother Aaron played Shura, although the two never had a scene together and their cousin Justin Cook played Yusuke. Linda Young (Genkai) and John Burgmeier (Kurama) are also mother and son.
 * Chris and Greg Ayres. Speed Grapher, Initial D, Dragon Ball Kai, Sengoku Basara...
 * In the English dub of Wicked City, Gregory Snegoff and Alexandra Kenworthy whom are son and mother play Taki and Mackie who are lovers.
 * Ewww...
 * Yuji Ueda and Omi Minami who are married in Real Life are cast in Martian Successor Nadesico as Akito Tenkawa and Ruri Hoshino. Thankfully however, they're not a couple seeing as Ruri is a Little Miss Snarker and Akito's pretty much in his late teens.
 * This gets a bit more awkward in Sensei no Ojikan/Doki Doki School Hours where they play teacher and student.
 * The Disney dub of My Neighbor Totoro cast real-life siblings Dakota and Elle Fanning as the Kusakabe sisters, Satsuki and Mei.
 * Voice actors Amanda Winn-Lee and Jason C. Lee are married, which makes their roles as the Bonnie & Clyde-esque protagonists of Dead Leaves amusing and Shigeru Aoba (Jason)'s  scene at   in The End of Evangelion hilarious.
 * Travis Willingham (Roy Mustang in Fullmetal Alchemist) and Laura Bailey (Lust) are married, which renders the violent confrontation between Mustang and Lust in episode 19 of Brotherhood Hilarious in Hindsight.
 * The Japanese voice actors of Haruhi and Hikaru from Ouran High School Host Club, along with Shiki and Mikiya in Garden of Sinners are married in Real Life.

Film

 * Sylvester Stallone's son Sage played Rocky Balboa's son in 1990's Rocky V, but turned down the role for the 2006 sequel, Rocky Balboa.
 * And Sly's brother Frank Stallone appeared in several Rocky movies.
 * Will Smith and his son, Jaden Christopher Syre Smith, played father and son in the 2006 film The Pursuit of Happyness.
 * Will Smith and his daughter, Willow Smith, played father and daughter in the 2007 film I Am Legend. Apparently Smith is a fair dad and wanted to give both his kids a movie.
 * Will Smith's two sons made cameo appearance in Men in Black 2 as two boys being neurolized in a climatic flying car chase scene.
 * All of the (many) movies that have starred real-life husband and wife Richard Benjamin and Paula Prentiss.
 * Freddie Prinze Jr. and Sarah Michelle Gellar were married during the production of the two Scooby Doo films.
 * In Carrie, Priscilla Pointer plays her daughter Amy Irving (Sue Snell)'s character's mother, something which he seems to have done in Sisters, too, with Jennifer Salt's mother playing her mother.
 * In Manos: The Hands of Fate, the actress who played the daughter, Debbie, Jackie Neyman, was actually the real-life daughter of the actor who played The Master, Tom Neyman. Well, that just puts a whole new spin on the ending, now doesn't it?
 * Partially subverted in the 2005 horror flick Devour: Jensen Ackles' real-life father played his character, Jake Gray,'s foster father.
 * Luke and Owen Wilson, brothers in real life, were together in The Royal Tenenbaums, but not as brothers (Luke played Ritchie Tenenbaum, while Owen played Eli, a friend of the Tenenbaum kids).
 * They were also in Disney's Around the World in Eighty Days—as the Wright Brothers.
 * Luke also appears with his other brother, Andrew, in Idiocracy. Andrew is Beef Supreme, one of the "corrections personnel" trying to kill Joe (Luke) in "Rehabilitation".
 * Lara Croft: Tomb Raider: Richard Croft was of course played by Jon Voight, Angelina Jolie's father. However, Jolie and Voight weren't getting along. Clever editing and writing allowed for them both to appear in the movie without ever being on the same set at the same time.
 * In the movie Eegah, writer/director Arch Hall Sr. cast his son Arch Hall Jr. as the boyfriend of his character's daughter. There were probably some awkward moments on that set.
 * Not as much as the second Underworld, where Scott Speedman even joked that he didn't know how to ask the director "how do I make love to your wife?".
 * In Kickboxing Academy, characters played by a real-life brother and sister (Christopher Khayman Lee and Chyler Leigh, despite the spelling) kiss. Awkwardness not avoided for viewers who know about this. This would not be the siblings' only onscreen kiss, leading to some speculations about those two....
 * Martin Sheen and his sons Emilio Estevez and Charlie Sheen often appear in film together, though not always as relatives. In Young Guns, Emilio's character is even more or less responsible for the death of Charlie's. A very memorable scene from Hot Shots 2: Part Deux featured Charlie's character writing a journal as a nod to his role in Platoon, which then fades into Martin Sheen parodying a monologue from Apocalypse Now. The two then stand up and give each other the thumbs up as their boats pass, both saying "I loved you in Wall Street" (another film they both starred in, where they played father and son). Then there was the film Men At Work, written by and starring Charlie Sheen and Emilio Estevez. They're not related in the film, however.
 * Emilio and Martin also appeared in Charlie's sitcom Two and A Half Men.
 * Then-couple Tom Cruise and Nicole Kidman in Eyes Wide Shut. Apparently director Stanley Kubrick wanted a real couple for the scenes together. (He had thought about a different famous actor couple before; Alec Baldwin and Kim Basinger.) We all know how that ended up.
 * Tom and Nicole also starred in Days Of Thunder and Far And Away as a couple.
 * In the lucha movie La Venganza de la Momia (The Vengeance of the Mummy), El Santo adopts a young boy after the monster of the title kills the boy's grandfather. The boy is played by one of Santo's sons.
 * Near the end of the last Lord of the Rings movie, there's a scene with Sam, Rosie, and their two children. The children seen are Sean Astin's (Sam) daughter and Sarah McLeod's (Rosie) baby daughter.
 * Donnie Darko, where the sister of the eponymous character (played by Jake Gyllenhaal) is played by Maggie Gyllenhaal, Jake's sister.
 * Jake also wound up co-starring with his eventual brother-in-law Peter Sarsgaard in Jarhead.
 * There is also Walter Hill's western The Long Riders, which starred James and Stacy Keach as Jesse and Franck James, David, Keith and Robert Carradine as Cole, Jim and Bob Younger, Dennis and Randy Quaid as Ed and Clell Miller, and Christopher and Nicholas Guest as Charley and Robert Ford.
 * Siblings John and Joan Cusack frequently appear together. In Say Anything... and Martian Child they played siblings. In High Fidelity they don't play siblings, just friends; however their mother does appear as the mother of John Cusack's character.
 * Zoolander is written by, directed by, and stars Ben Stiller. No wonder, then, that his father, Jerry Stiller, also gets a prominent role. His mother, Anne Meara, also features in a cameo. Not to mention his wife, Christine Taylor, playing his love interest.
 * And the two play opponents of each other in Dodgeball: A True Underdog Story.
 * In Run Lola Run, the blind woman who gives Manny a phone card is his mother in real life.
 * In the comedy Blades of Glory, Will Arnett and Amy Poehler (married in real life) play a pairs team of brother and sister. Towards the end of the movie, their real-life relationship is replicated, with disturbing results.
 * Real-life mother and daughter Diane Ladd and Laura Dern have played mother and daughter in four movies (cf Those Two Actors: White Lightning, Wild at Heart, Citizen Ruth, and Daddy and Them.
 * In Grizzly Mountain, Dan Haggerty stars in the show - as do his two children, Dylan Haggerty and Megan Haggerty. Dylan is one of the protagonists, while Megan is the other sister. They have no apparent relationship to Dan Haggerty's character. All three siblings also share names with their actor counterparts.
 * In the first scene of Jay and Silent Bob Strike Back where we see the title characters as babies, Silent Bob is played by Kevin Smith's daughter, Harley Quinn Smith. (No, really.) Smith's wife also appears as one of the villainous jewel thieves, who noticeably takes no part in the gang's big scene as she's getting the van ready. Smith says on the commentary, "A better husband probably would have given her more to do." He does make an Actor Allusion out of it though. She comments to the others, "The fat one is creeping me out."
 * She also appears as a receptionist in Jersey Girl and is finally given a more important role in Clerks 2 as Dante's fiancé.
 * Kevin Smith's real-life mother plays the "Milkmaid" in Clerks.
 * Kenneth Branagh and Emma Thompson, then husband and wife, played Benedick and Beatrice in Branagh's Much Ado About Nothing. Now a Funny Aneurysm Moment.
 * They also played Roman and Margaret in Dead Again and Henry V and Katherine in Henry V. And a couple of other things.
 * No one knew that porn stars Amber Lynn and Buck Adams were brother and sister until they were cast in the same film and were scheduled to have sex with each other. They put a stop to that pretty damned quick by revealing their relationship to one another.
 * During their marriage, Elizabeth Taylor and Richard Burton appeared in several films together; the most famous is Who's Afraid of Virginia Woolf?. Not that there's any irony in that.
 * Paul Newman and his wife Joanne Woodward appeared in ten films together.
 * Henry Fonda and his daughter Jane played father and daughter in On Golden Pond.
 * Wah and Qiu Yuen trained under the same master at the China Drama Academy. They've appeared in quite a few martial arts films as a couple, most notably Kung Fu Hustle.
 * Siblings Spencer and Abigail Breslin played siblings in Raising Helen.
 * Judd Apatow often casts his wife and daughters in his films, such as Knocked Up and Funny People. His justification for using his own kids is that he doesn't like child actors and would rather not have to work with them.
 * Wings is not the only place where Amy Yasbeck and John Ritter have been on screen together. They also appear in both Problem Child movies, though Yasbeck inexplicably plays two different characters.
 * They were also on an episode of The Cosby Show as an expecting couple whose baby is being delivered by Dr. Huxtable.
 * Though, strangely enough, this was years and years before they were even dating.
 * The Great Buck Howard stars Colin Hanks; his more famous dad Tom shows up briefly as his character's father.
 * Denis Lawson, who played the Mauve Shirt pilot (and very successful Ascended Extra in the EU) Wedge Antilles in the Star Wars OT, is the uncle of Ewan McGregor, who played the young Obi-Wan in the prequel trilogy. Apparently Denis told his nephew not to take this gig.
 * Lawson was also offered the chance to play a walk-on role in Revenge of the Sith as Captain Antilles - the pilot who Vader strangles in A New Hope. Alas, he didn't take it.
 * Monica Belluci and Vincent Cassel are married and have appeared as a couple in L'Appartement, Dobermann and Irreversible.
 * Father and daughter Ryan and Tatum O'Neal played two grifters (who are implied to be father and daughter) in Paper Moon.
 * In the film version of Danny, the Champion of the World, Jeremy Irons played Danny's father and his son Samuel Irons played Danny. Additionally, Jeremy Irons' father-in-law (Samuel's grandfather) Cyril Cusack played Doc Spencer.
 * The photograph of Danny's late mother was also in fact a photograph of Samuel Irons' actual mother (Jeremy Irons' wife, and Cyril Cusack's daughter, actress Sinéad Cusack).
 * In the 2003 film, It Runs in the Family, Kirk Douglas, his son Michael. and Michael's son Cameron played three generations of a family. Michael's mother is played by his real-life mother, Kirk's former wife, Diana Dill.
 * Real-life siblings Matthew and Rebecca Pidgeon play Dickie and Catherine Winslow, respectively, in The Winslow Boy.
 * Humphrey Bogart and wife Lauren Bacall starred in three movies as a couple after their Romance on the Set in To Have and Have Not: The Big Sleep, Dark Passage and Key Largo.
 * He also played along with Mary Phillips, his second wife, in Broadway's Like That as husband and wife.
 * In Kiss Kiss Bang Bang, Robert Downey Jr.'s son Indio plays RDJ's character as a young child.
 * John Mills and his daughter Haley Mills both starred in the movie Tiger Bay, he playing a police detective and she the lone witness to a murder he is investigating. The two made other movies together as well.
 * In The Family Way, they play a father- and daughter-in-law.
 * Then-couple Jeff Goldblum and Geena Davis costarred in The Fly, Transylvania 6-5000 and Earth Girls Are Easy.
 * In the film Miracle, USA hockey player Buzz Schneider was played by his son Billy. Proof.
 * Real-life couple Kurt Russell and Goldie Hawn appear together as a couple in Overboard.
 * On the subject of Kurt Russell, his first wife, Season Hubley, makes an appearance in Escape from New York, and his son (with Goldie Hawn), Wyatt, has cameos in both Escape From L.A. and Soldier.
 * Real life husband and wife Hume Cronyn and Jessica Tandy as Joe and Alma Finley in Cocoon.
 * Jamie Lee Curtis' mother, Janet Leigh, had a cameo appearance in Halloween H20.
 * In The Good Son Macualay Culkin's real life sibling Quinn and Rory Culkin appear as Henry's siblings Connie and Richard whom
 * Also, in Richie Rich Rory plays the younger Richie.
 * And in Home Alone Kieran plays Macaulay's cousin.
 * In the 1938 film of A Christmas Carol, Bob Cratchit, Mrs. Cratchit, and Belinda Cratchit were played by Gene, Kathleen, and June Lockhart.
 * In the sixth Harry Potter movie, the 11-year-old Tom Riddle is played by Ralph Fiennes' nephew, Hero Fiennes-Tiffin.
 * And in the seventh, the death of is announced by Bill Weasley, who is the former actor's son.
 * In the epilogue of the eighth movie, Draco Malfoy's future wife Astoria is played by Jade Olivia, the then-real-life girlfriend of Draco actor Tom Felton.
 * Anna Friel apparently really wanted to play Tonks so that she could act alongside David Thewlis, her real-life partner. The role went to Natalia Tena.
 * The very first includes director Chris Columbus' daughter Eleanor as Susan Bones. Also siblings Derek and Julianne Hough played two unnamed Hogwarts' students.
 * There was also this pair of twins in there somewhere...
 * In the film Barney's Version, Dustin Hoffman's son Jake plays his grandson.
 * In Daddy's Little Girls, the main character's three daughters are played by sisters China, Lauryn and Sierra McClain, and their names in the movie are China, Lauryn and Sierra.
 * In Eve's Bayou, Jurnee Smollett(Eve)'s real life brother Jake plays Eve's younger brother Poe.
 * In Bridesmaids, Melissa McCarthy's husband Ben Falcone has a small role as a man her character (Megan) hits on
 * Gigli was centered on this. As a vehicle for Ben Affleck and Jennifer Lopez's relationship, it died along with public interest over their coupling, along with Kevin Smith's Jersey Girl which starred Affleck and had Lopez in a smaller role.
 * While filming Terminator 2: Judgment Day, James Cameron took advantage of the fact that Linda Hamilton has an identical twin sister in order to save on his special effects budget. In three scenes that required two "Sarah Connors" to be on screen at the same time (the playground scene where Conner is trying to warn everyone about the oncoming nuclear war, the CPU reprogramming scene, and the scene where the T-1000 had taken Sarah's form), Cameron used Hamilton's sister, Leslie Hamilton Gearren, as a double rather than using CGI to achieve the same effect.
 * In the Soviet film Teens in the Universe, the leader of the Human Aliens and his son Agapit are played by the Real Life father-and-son Igor and Vadim Ledogorov.
 * Tim Burton often casts his real life girlfriends (first Lisa Marie and then Helena Bonham Carter) with the latter getting the more meatier parts than the former as Bonham Carter was already a well-respected Academy Award nominated actress before she and Burton hooked up.
 * In Disney's Hocus Pocus, "the Master" and his wife are played by (uncredited) real-life siblings Garry and Penny Marshall.
 * In The Shawshank Redemption, the old photo of Red, at the time of his incarceration, which is shown briefly when Red is up for parole, is not an old photo of Morgan Freeman, but rather a photo of Freeman's son.
 * The real parents of The Goonies were cast as their parents for the final reunion, save for Mikey and Brand's parents being played by established actors.

Live-Action TV
""I remember Martin [Gero] actually said to us once, 'Now remember you guys are supposed to be brother and sister.' And we were laughing because we were treating each other so horribly, we could only be brother and sister. ... He was like, 'Remember you're brother and sister,' and we were like, 'Yeah--? Thank you for reminding us?'""
 * Emilio Estevez and his daughter also have a brief appearance in an episode of The West Wing, in "archival video" of a younger Jed Bartlet and daughter Zoe.
 * Martin Sheen's daughter Renee has a small recurring role as staffer Nancy, who interacts with the President from time to time.
 * An episode of Fantasy Island called "What's the Matter With Kids?" features Steve Allen and Jayne Meadows as a husband-and-wife pair of child psychologists.
 * One Highlander the Series episode had an appearance of Adrian Paul's then-wife Melani as an escaped female con hired to seduce Duncan. (She played the character until the plastic surgery, then Alexandra Vandernoot took over)
 * Geraint Wyn Davies' real-life son guest starred in one season 3 episode of Forever Knight.
 * Another episode had the then-boyfriend of Catherine Disher, aka Natalie, as a guest star
 * Robert Reed's real life daughter appeared in one episode of The Brady Bunch.
 * Lucille Ball and Desi Arnaz, who starred in several classic comedy films in addition to producing and starring in I Love Lucy. Unfortunately, they had Real Life marital trouble during the course of the series and divorced after the final episode had aired.
 * Their children, Lucie Arnaz and Desi Arnaz Jr., starred in Lucille Ball's later shows.
 * In Smallville twins Shawn Ashmore and Aaron Ashmore both played parts—one an early Freak of the Week bit part and the other a cast regular good guy—nobody ever notices they look alike.
 * On The Odd Couple TV series, Jack Klugman played bitter divorcee Oscar Madison, and his wife, Brett Somers, played Blanche, Oscar's ex-wife. During the series' run, Klugman and Somers really did separate, though their marriage didn't officially end until Somers died in 2007.
 * Friends (Jennifer Aniston and Tate Donovan)
 * Matthew Perry's father played Joshua's (Tate Donovan's character) father in one episode.
 * When Julia Roberts guest starred, her real life sister played her assistant.
 * Roberts guest starred in the first place because she was dating Matthew Perry at the time.
 * While Brad Pitt was married to Jennifer Aniston he appeared as Monica, Rachel and Ross' old high school friend. His character, Will, and Ross started the rumor about the 'hermaphrodite cheerleader from Long Island' aka Rachel.
 * On Gilmore Girls, The chemistry between Rory and Jess was made a little more obvious due to the fact that Milo Ventimiglia was the real life boyfriend of Alexis Bledel when he joined the show. In an odd coincidence, they broke up roughly around the same time that Rory and Jess see each other for the final time.
 * The new Battlestar Galactica Reimagined has four minor characters played by real-life relatives of the main cast. Bodie Olmos ('Hotdog') is the son of Edward James Olmos (Admiral Adama), Lymari Nadal (Giana) is Olmos's wife, Susan Hogan, the wife of Michael Hogan (Saul Tigh) plays the lead judge in Baltar's trial, and Kerry Norton, Jamie Bamber's ('Apollo') wife plays a medic.
 * In a behind the scenes example, the show's iconic cover of Bob Dylan's "All Along the Watchtower" (and several other tracks) are preformed by Brendan McCreary, the brother of the show's composer, Bear McCreary.
 * In the episode Greetings from Earth in the original series, most of the children are played by children of the series creator Glen A. Larson or star Lorne Greene.
 * Babylon 5 had Bruce Boxleitner and Melissa Gilbert, husband and wife, playing husband and wife. As well, a photo from their real wedding is used in the show as one from the characters' wedding. On the show they don't work out.
 * Oddly, Melissa Gilbert was The Other Darrin in this example. An episode the previous season had featured a different actress as his wife, but she was unavailable for the second appearance.
 * Word of God is that Melissa Gilbert took the role for less money than she usually gets, as a favor to her husband.
 * Jeremiah: In the episode Moon in Gemini, cast regular Ingrid Kavelaars' character Erin has a twin sister named Lauren, played by... real-life twin sister Monique Kavelaars.
 * Two of a Kind, So Little Time, Sister, Sister, Double Trouble, and Sweet Valley High are all built around twin sisters being played by twin sisters (first two the Olsens, the other three the Mowrys, Sagals, and Daniels respectively).
 * Peter DeLuise, the director of Stargate SG-1, occasionally also made cameo appearances. His brother David played as a love interest to Carter.
 * His other brother Michael DeLuise appeared as "Colonel Danning" in Wormhole X-Treme! and father Dom DeLuise as Urgo.
 * As well as his wife Anne Marie DeLuise (nee Loder) as Farrell in The Other Side and Cameron Mitchell's high school sweetheart Amy Vanderburg in Bounty.
 * Real-life siblings David and Kate Hewlett also play brother and sister onscreen in Stargate Atlantis in the aptly named episode "McKay and Mrs. Miller". Fans loved her so much that TPTB brought her back for three more episodes.
 * This was actually Art Mimicking Life - in "The Siege" McKay was originally to have been composing the video to his brother. David Hewlett convinced them to shift it to sister, as he had no brothers, but did have a sister who was an actress, should they ever want to go that route later on in the series...
 * Hewlett said in an interview that in their first episode together the director instructed them to act like brother and sister, forgetting that they actually were.

"Michael: Marry me! ... That's so wrong... on so many levels."
 * Space: 1999, starring Martin Landau and his wife Barbara Bain, both also having starred before in the show Mission: Impossible.
 * And in the Mission: Impossible revival series, Barney's son was played by the actor's son.
 * Kelly Ripa and Mark Consuelos, both regulars on All My Children, were married in 1996...and then their characters got married.
 * In Star Trek: Voyager, "Q2", father and son John and Keegan de Lancie play Q and "Q Junior". Also an instance of Plot-Relevant Age-Up—Q Junior is an adolescent, but the last time we saw him, three seasons earlier, he was an infant. Of course, since he's a Sufficiently Advanced Alien, he can look however he wants.
 * Donald Sutherland was to play the father of his son Kiefer's character, Jack Bauer, on 24, but was unavailable at the time of filming and was replaced by James Cromwell.
 * "Far Beyond The Stars", an Elseworld episode of Star Trek: Deep Space Nine in which the regulars were writers for a 1950s science fiction magazine, had Nana (Kira) Visitor and Alexander (Bashir) Siddig, who were married at the time, as a married couple based on C. L. Moore and Henry Kuttner.
 * In the Farscape trilogy Look at the Princess, the simulations of John Crichton's son and daughter are played by Ben Browder's children.
 * Additionally, Ben Browder's wife, Francesca Buller, has played multiple alien characters, notably War Minister Ahkna.
 * Browder's children show up again in Stargate SG-1 as a pair of random kids running past SG-1 in a village.
 * The Suite Life of Zack and Cody, with the Sprouse brothers Dylan and Cole as the title characters.
 * And the same with any other Disney movie or television show with twins. Disney loves twins and uses them as much as possible.
 * Third Watch: Paramedics Carlos Nieto and Holly Levine dated and got married in the final season. They were played by real life husband and wife Anthony Ruivivar and Yvonne Jung.
 * Another extreme example was the two-part episode "Sandkings" in the 90's remake of The Outer Limits. Beau Bridges played the episode's main character, Dr. Simon Kress, his father Lloyd Bridges played Simon's father, and his son Dylan played Simon's son.
 * Little House On the Prairie sports a peculiar variation. Melissa Gilbert, playing Laura Ingalls, is of a different family than her real-life brother, Jonathan Gilbert, playing Willie Oleson. In reality, they were both adopted by the same family but are not blood related. It gets even better because Melissa Gilbert's in-show brother, Matthew Laborteaux, is the real-life brother of Patrick Labyorteaux (Matthew dropped the "y" from his surname), playing Matthew's friend on the show, Andrew Garvey, which are also both adopted! To top that, the role of Carrie Ingalls was played by twins Lindsay and Sidney Greenbush. While it's not rare for twins to play the same role, especially as a baby, there was an episode where both of them played side by side, when Carrie's character created an imaginary friend, played by her actual sister! Even more, the twins have a brother which also appeared as a guest star on the show!
 * The '80s Disney TV movie The Thanksgiving Promise features Beau, Lloyd, Lloyd's wife Dorothy, Beau's other son Jordan, and an uncredited Jeff.
 * In one episode of The Last Detective, Georgia Moffett guest-starred alongside her dad—star Peter Davison. The production team wanted the former's character to flirt with the latter's. One or both of them deep-sixed that idea pronto.
 * Peter Davison and Georgia Moffett, real-life father and daughter, played a father and daughter on Fear Stress And Anger.
 * (And for the hat-trick) A particularly unusual variant in Doctor Who: in 2008 Georgia Moffett played the daughter of David Tennant's (Tenth) Doctor - who is a regeneration of the same character played five 'lifetimes' earlier (the Fifth Doctor) by her real-life father Peter Davison between 1981-84. The pair started dating afterward, and now have a child and are engaged to be married.
 * An Eighth Doctor Doctor Who audio titled "An Earthly Child" features Paul McGann's real life son as the Doctor's great-grandson (i.e. Susan's son).
 * In Eleventh Doctor Matt Smith's first episode, the production staff, looking for an actress to play a young version of new companion Amy Pond, asked Karen Gillan (the adult Amy) if she had any relatives. Karen mentioned a young cousin of hers, Caitlin Blackwood, and the production team decided to audition her. The two had never met before shooting started.
 * Blackwood appeared again at Amy's wedding at the end of the series, presumably as one of Amy's cousins, even further driving this trope home.
 * David Troughton, son to Second Doctor Patrick Troughton, made an appearance in his father's final story 'The War Games' in 1969. He returned as different characters in the 1972 Third Doctor adventure 'The Curse of Peladon' and the 2008 Tenth Doctor adventure "Midnight"...not to mention various 21st century audio Doctor Who dramas.
 * Talking of Patrick Troughton, Jack Watling (Professor Travers in the Great Intelligence stories) was the father of Deborah Watling (the Doctor's companion Victoria).
 * In the original production of the stage play "Doctor Who and the Daleks: Seven Keys to Doomsday", the companion character is Jenny, played (oddly enough) by Wendy Padbury (Zoe Herriot). In the Big Finish version she's played by Padbury's daughter, Charlie Hayes.
 * In the Series 6 episode "The Impossible Astronaut", W. Morgan Sheppard plays the character of Canton Delaware as he appears in 2011, and his son Mark Sheppard plays the same character in 1969.
 * Incidentally they also do this in an episode of NCIS (6.13; "Broken Bird") with Mark Sheppard playing a young version of W. Morgan Sheppard's character in Ducky's flashbacks.
 * Diagnosis: Murder starred Dick Van Dyke as crimesolving doctor Mark Sloan, and co-starred his own son Barry Van Dyke as his character's son, police detective Steve Sloan. Other members of the Van Dyke family appeared at various times during the show's run, including Dick's brother Jerry and daughter Stacy in one episode each as Dr. Mark's brother and daughter respectively. Barry's four children all appeared in multiple episodes, although not as Sloan family members: Carey as six different characters in as many episodes; Shane as four, the last of whom became a regular supporting role in the show's concluding months; Wes as three; and Taryn in three episodes. All four appeared together in two separate episodes, which therefore share the highest rating of 6.0 on the Van Dyke Scale...
 * The Dick Van Dyke Show also had a few episodes with Jerry Van Dyke as Stacey Petrie, Rob's sleepwalking brother.
 * The Wonder Years featured Danica McKellar as Kevin's main love interest, and her real-life sister Crystal McKellar in a recurring role as an unrelated character who was also Kevin's sometime girlfriend.
 * Benjamin Bratt and Julia Roberts were dating when they starred in a memorable episode of Law and Order. Mostly notable for the fact that Roberts attempted to seduce Bratt's married character, leading to a venomous and hateful series of betrayals. One wonders if they might not have had some real-life problems to work out...
 * Probably, since they didn't stay together.
 * Another Law and Order example (sort of) derives from when Jill Hennessy was on Law and Order as Claire Kincaid. Jill was filming some scenes from a crossover with Homicide: Life on the Street and the filming coincided with the filming of Law and Order, so Jill's identical twin sister Jacqueline came in and filled in for Jill during some courtroom scenes.
 * House co-stars Jesse Spencer and Jennifer Morrison were dating at the same time as their characters, Dr. Chase and Dr. Cameron, started their romantic relationship.
 * Inversely, a few months after Chase and Cameron made their relationship official in the third season's finale, Jesse Spencer and Jennifer Morrison decided to call off their engagement.
 * Billy Ray Cyrus and his daughter Miley play Hannah Montana's dad and the title character, respectively.
 * And his other daughter Noah is an extra.
 * Mateo Arias made a cameo appearance as Rico's brother. Rico is played by Moises Arias.
 * On iCarly Gibby (Noah Munck)'s brother Guppy is played by his little brother Ethan.
 * A pretty interesting one from The King of Queens: in a flashback to the childhood of Jerry Stiller's character Arthur Spooner, Arthur's father is played by Jerry's son Ben Stiller.
 * Also Doug's cousin Danny is played by Kevin James' brother in Real Life, Gary Valentine.
 * Madylin Sweeten and her younger twin brothers, Sawyer and Sullivan, play Ally Barone and her younger twin brothers, Geoffery and Michael, respectively, on Everybody Loves Raymond
 * Simon Baker's wife appeared in an episode of her husband's hit show The Mentalist as the widow of that episode's victim.
 * Tim Kang's wife plays one of the women in the bar during Cho's Instant Seduction scene in "Crimson Casanova" (she's the one who walks off in disgust when he suggests a threeway), a Reality Subtext which makes the scene even more hilarious.
 * Grey's Anatomy's Derek Shepherd's mother is played by Tyne Daly; ironically, Daly is tied by parental roots to two actors from Private Practice, one fictional (she played Amy Brenneman (Violet)'s mother in Judging Amy) and one real (Tim Daly (Pete) is Tyne's baby brother).
 * In Private Practice, Idina Menzel plays a patient's mother and a potential love interest. Menzel is the real-life wife of Taye Diggs, who plays Dr. Sam Bennett.
 * In It's Always Sunny in Philadelphia, Charlie Day's character has an unrequited crush on a waitress played by his real-life wife, Mary Elizabeth Ellis. Also, Rob McElhenney (Mac) is married to Kaitlan Olson (Sweet Dee); they met when she auditioned for her part. In another episode with a Shout-Out to One Flew Over the Cuckoo's Nest, the person who was playing the role of "Chief" was actually Will Sampson's son.
 * Additionally, in the episode "Mac Bangs Dennis' Mom" Danny DeVito's daughter Lucy plays the waitress Frank lusts after in the restaurant (as his date talks about how wonderful it is to have children), as well as the young woman who compliments "DB" in "The Gang Finds a Dumpster Baby".
 * In Family Ties, Tracy Pollan played the girlfriend of Michael J. Fox's character. In Bright Lights Big City, Tracy Pollan played the cousin of Michael J. Fox's character. The two of them married later that year, and are still married to this day. Tracy Pollan has also made a guest appearance on Spin City, as the high school flame of Michael J. Fox's character.
 * Before Tracy Pollan, Michael J. Fox had dated Nancy McKeon. The two of them played love interests on two made-for-TV movies, High School USA and Poison Ivy.
 * In Life With Mikey, Michael J. Fox is the titular character. His sister, Kelli Fox, has a minor role.
 * On Heroes, the actors playing Ted Sprague and Sandra Bennet are married in real life. In one episode, Ted threatens to kill Sandra. In the episode commentary, the actor playing Ted observes, "Yeah, our kids aren't gonna be allowed to watch this one."
 * The fact that Hayden Panettiere and Milo Ventimiglia were dating is going to make for some awkward television considering that Milo's Heroes character is her character's uncle.
 * If those two end up marrying, I doubt they'll let their kids watch the recent episode . Assuming they let their kids watch the show at all.
 * On the last couple of seasons of Growing Pains, Chelsea Noble played the romantic interest of Kirk Cameron's character. They ended up getting married in the show, and then later married in Real Life.
 * And then even later, Noble played Cameron's love interest in the short-lived WB series Kirk.
 * They've since appeared together in the Left Behind movies. (Although Cameron plays the main character and Noble plays...the anti-Christ's girlfriend.) They're both now evangelical Christians.
 * ...and even worse than that, reportedly, Cameron won't even kiss anyone other than Noble now. She's supposedly in Fireproof (uncredited) in Cameron's kiss scenes with his movie wife (played otherwise by Erin Bethea).
 * In the Sabrina the Teenage Witch TV series, Melissa Joan Hart's real life sister Emily played Sabrina's cousin Amanda. She then played Sabrina on the animated series while Melissa Joan Hart played her aunts.
 * On the 1980s British TV series A Fine Romance, main characters Mike and Laura were played by real-life spouses Michael Williams and Judi Dench.
 * In the Star Trek: The Next Generation episode "The Inner Light", the son of Kamin, the person whose life Picard is experiencing, was played by Patrick Stewart's son Daniel.
 * Father-son example: in Romeo!, Master P makes occasional guest appearances as the father of the title character, played by his son Li'l Romeo.
 * Extreme example: Michael, Nat, and Alex Wolff (father and sons) play a father and his two sons in The Naked Brothers Band.
 * On top of that, Jesse, Alex's May–December girlfriend, is actually his cousin.
 * The character of Compo Simmonite died on Last of the Summer Wine following the death of the actor Bill Owen. Several episodes later and after the funeral, Compo's long-lost son moves into town and is played by Bill Owen's real-life son Tom Owen.
 * Pauline Quirke and Linda Robson, who played sisters Sharon and Tracy in Birds of a Feather, have been friends since primary school, enabling the opening credits to use genuine photos of them growing up together.
 * Another extreme example: a two-parter of The Bill features three generations of the Woodward acting dynasty. Edward (an old crook), his son Tim (as his love child) and Tim's son Sam (as the first character's grandchild, not via the second).
 * Kojak featured Telly Savalas and his brother George as Det. Stavros.
 * Power Rangers Zeo introduces us to David Trueheart, Tommy's long-lost brother... played by Eric Frank, actual brother to Tommy's actor, Jason Frank.
 * M*A*S*H star Alan Alda's father Robert Alda starred as a visiting/rival surgeon a couple times. One of the times, Alan Alda's brother also guest-starred as a medic.
 * The photograph on Col. Potter's desk, supposedly of Potter's wife Mildred, was actually a picture of Harry Morgan's real-life wife, Eileen Detchon.
 * In Due South Fraser's (Paul Gross' character) mother was played by Martha Burns ...who is Paul Gross' wife. They also starred together in the series Slings and Arrows, as former lovers.
 * Buffy the Vampire Slayer took advantage of the fact that Nicholas Brendon (Xander Harris) has an identical twin, in an episode where there are two Xanders.
 * Kelly Donovan (Brendan's twin) stood in for Nicholas Brendon on multiple occasions during Buffy's production run. Besides the episode mentioned above, Donovan subbed for his brother during the fight scenes in the episode "Intervention", because Nicholas Brendon had pneumonia at the time.
 * Adam Busch (Warren) and Amber Benson (Tara), respectively, were dating, and Joss Whedon actually told Adam, "You're gonna kill your girlfriend," to which the reply was "Warren gets a girlfriend?" "No, I mean your real girlfriend." Eight years later, by the way, they're still together. This relationship was actually the inspiration somewhat for the Buffy fanfic Difficult to Fight Against Anger.
 * Alyson Hannigan crossed over to guest star on Angel alongside her now-husband Alexis Denisof
 * David Boreanaz' wife Jaime Bergman appeared in one season 5 Angel episode.
 * Dollhouse similarly took advantage of Enver Gjokaj (Victor) having an identical twin brother. He stood in as the second Victor in a dream sequence.
 * Dollhouse had another example of real-life relatives: the series finale has Eliza Dushku's younger brother Nate as Clive Ambrose's latest body. Her real-life boyfriend, Rick Fox, also cameoed.
 * Nate was also the gunman in one of Angel's flashbacks in Eliza's final appearance on that show.
 * Several episodes of Monk guest-star Brooke Adams (aka Mrs. Tony Shalhoub), each time as a different character.
 * Adams also guest-starred on Wings as a nun who is helped by Shalhoub's character Antonio.
 * Speaking of Wings, in addition to Shalhoub and Adams, a handful of episodes featured guest spots by relatives of the cast.
 * Tim Daly's sister Tyne played a wealthy woman who attempts to make Brian a kept man.
 * Tim Daly's wife, Amy Van Nostrand, played a woman in a married couple who befriends the Hacketts.
 * Amy Yasbeck's husband John Ritter played Casey's estranged husband Stuart.
 * Emily, the estranged daughter of Gerry Standing in New Tricks is played by Dennis Waterman's daughter Hannah.
 * Subversion:
 * James Roday and Maggie Lawson, who are dating in real life, star in the Fear Itself episode "In Sickness and in Health" as a couple about to get married. The two are also castmates in Psych, and their characters officially entered a relationship in Season 5.
 * Veronica Mars Logan Ecchols' parents are played by real-life husband and wife Harry Hamlin and Lisa Rinna.
 * Michael Scott's girlfriend Carol in seasons 2 & 3 is played by Steve Carell's wife, Nancy Walls.
 * Arrested Development: The woman Gob (Will Arnett) marries on a dare is played by Arnett's wife, Amy Poehler. The situation was reversed years later when Poehler got her own show, Parks and Recreation, and Arnett appeared in one episode as Leslie (Poehler)'s horrible blind date.
 * Arrested was fond of this trope. In a later episode, Michael (Jason Bateman) hires a woman, played by Bateman's real-life sister Justine, to work at the Bluth Company. He thinks she is his ; she's actually a.

"Stephen: How big was your profit margin last year? Madeleine: I don't know what that means, Daddy."
 * Tatort (NDR; Hannover): The actress Maria Furtwängler who plays KHK Charlotte Lindholm is the daughter of Kathrin Ackermann who portrays Charlottes mother Annemarie Lindholm.
 * Semi-example: Shirley Jones, who is/was David Cassidy's stepmother, played his mother in The Partridge Family. AIR neither was consulted on the casting of the other.
 * After he gained more creative control on Sliders, Jerry O'Connell got his real-life brother added to the regular cast, playing his long-lost brother. When Jerry departed the show, his brother went with him.
 * Charlie O'Connell would later make an appearance as the brother of Jerry O'Connell's character in Crossing Jordan.
 * In the Red Dwarf episode "Timeslides" Lister's younger self was played by Emile Charles, Craig Charles's younger brother. Baby Lister in "Oroboros" was played by Danny John-Jules's nephew, Alexander John-Jules.
 * The mechanoid and blob incarnations of Camille in "Camille" were played by Robert Llewellyn's then-girlfriend (now wife) Judy Pascoe. In his memoir The Man In The Rubber Mask Llewellyn claims that the publicity shot of Kryten and Camille is in his parents' photo album: "That's our elder son and his wife and children, that's our daughter and her children, and that's our middle son who's a robot and his girlfriend."
 * In St. Elsewhere, Dr. Craig and his wife were played by real-life husband and wife William Daniels and Bonnie Bartlett.
 * Briefly reprised in Boy Meets World, where Mr. Feeney (Daniels) fell for the college's dean (Bartlett). In fact, Daniels and Bartlett have played a romantic couple on no less than four occasions: Killer on Board (1977), Touched By an Angel, Boy Meets World, and St. Elsewhere. Apparently, they are a living aversion to the Couple Bomb both in real life and onscreen (they've been married since 1951).
 * Another Boy Meets World example: Topanga's parents were played by the husband-and-wife Michael McKean and Annette O'Toole for one episode. Also, Ben Savage's brother Fred Savage appears in one episode as a creepy lecherous college teacher.
 * The first season The Man from U.N.C.L.E. episodes "The Quadripartite Affair" and "The Giuoco Piano Affair" were two of the relatively few episodes that gave Illya Kuryakin (played by David McCallum) the Girl of the Week. She was played in both episodes by Jill Ireland, who was at the time of filming married to McCallum.
 * On Lost, Benjamin Linus is played by Michael Emerson. His wife Carrie plays Ben's mother Emily. Thankfully, Squick is avoided because Emily and thus only appears during baby Ben's birth and  to young Ben.
 * Father and son Rene Auberjonois and Remy-Luc Auberjonois played father and son in an episode of L.A. Law.
 * Speaking of LA Law, husband-wife actors Michael Tucker and Jill Eikenberry were both regulars on that show and also appeared together in several late '80s/early '90s TV movies that they produced.
 * How I Met Your Mother managed to bring in Alyson Hannigan's husband, Alexis Denisof, as a love interest for Robin. Also, David Burtka, Neil Patrick Harris's boyfriend, played Lily's high school boyfriend.
 * Not to mention that Josh Radnor, who plays Ted, is dating Lindsay Price who played Cathy the girl who couldn't shut up in the episode Spoiler Alert. And Cobie Smulder's Fiancee, Taran Killam, played Blauman a co-worker of Marshall and Barney's. There's a strange alternate universe episode in here somewhere.
 * The Heartwarming Orphans from The Colbert Report Christmas Special are Madeleine, Peter, and John Colbert. Madeleine also appeared aged eight in the Getty Oil segment on The Daily Show, producing some adorable outtakes.

"Everyone, upon seeing the two in the same room: You two could be sisters!"
 * His brother Ed Colbert is a copyright lawyer, and appeared on the show during the Shepard Fairey 'Hope' poster fair use debate.
 * Jon Stewart's son, Nathan, has appeared on The Daily Show at least twice. The funniest moment being when he played a cheap Youtube version of his father (he's 5, people). Jon's inability to hold his laughter when the camera cut back was priceless.
 * Gossip Girl stars Penn Badgley (Dan) and Blake Lively (Serena) date in real life as well as in the show.
 * Someone might say that the Gossip Girl one-episode Vanessa/Chuck hookup and kiss might be imputable to the two actors playing the characters, Jessica Szohr and Ed Westwick, dating, but given the fact that the writers of the show seem to be on crack most of the time, that's highly debatable. Also, the set brought Sebastian Stan (Carter Baizen) and series regular Leighton Meester (Blair Waldorf) together.
 * Toward the end of its run One Day at a Time had as regulars both Nanette Fabray and her niece, Shelley Fabares, providing an interesting side-by-side example of how anglicizing your name for the stage seemed less necessary from one generation to the next. Casual viewers didn't always know they were related, especially if they didn't realize their last names are pronounced the same.
 * Real-life couple Michael and Susan Hogan played the parents of Dana Fairbanks in The L Word, and the parents of Myka in Warehouse 13
 * Most of the random characters on The Mighty Boosh are friends and family of Noel and Julian. The relative with the largest role would be Vince's girlfriend's nephew who plays the shaman Kirk. Or maybe Naboo, who is played by Noel's brother.
 * An interesting but slightly obscure example: Martin Sheen's daughter plays one of the secretaries of the Oval Office in The West Wing. In the season finale, the President asks about her mother, and then said, "Tell her I'm looking forward to seeing her again sometime soon, would you please?", which is actually a shout out to his own wife.
 * Martin Sheen also appeared on an episode of Two and A Half Men in which he played the father of Charlie's Stalker with a Crush. Charlie is, of course, played by Charlie Sheen. In the same episode, Martin Sheen's character gets in a relationship with the mens' mother, much to their horror.
 * And Emilio Estevez has also appeared on Two and A Half Men.
 * On Seinfeld, Julia Louis-Dreyfus's sister Lauren Bowles made occasional appearances as a waitress in the coffee shop that the characters frequent.
 * Speaking of Julia Louis-Dreyfus, she and her future husband Brad Hall were castmates on Saturday Night Live. Several years later, Julia guest-starred on an episode of The Single Guy, which was created and produced by Hall.
 * Zooey Deschanel guest-starred in an episode of Bones, which stars her sister Emily, as Emily's character's cousin. The writers took the golden opportunity to Lampshade the hell out of this during said episode.


 * She also appeared in the video for The Postal Service's "We Will Become Silhouettes", alongside her now-husband Ben Gibbard.
 * The French series Kaamelott seems to have been cast largely from creator (and lead actor) Alexandre Astier's family. In particular, his real-life father, mother, and half-brother appear as his father-in-law, mother-in-law, and brother-in-law, respectively. Note they're all professional actors anyway, so it hardly hurts the show.
 * On Parks and Recreation, Ron Swanson's Femme Fatale ex-wife is played by Megan Mullally, who is married to Nick Offerman in real life.
 * In one episode, Leslie had a disastrous date with a strange Cloudcuckoolander played by Will Arnett, Amy Poehler's husband in real life.
 * In the first season of Get A Life, Chris Elliott's character's father was played by his real-life father Bob Elliott.
 * The second and third seasons of SeaQuest DSV has Peter and Michael DeLuise on the main cast, though their characters are not related. In one episode, Dom DeLuise appears as the father of Michael's character, and David DeLuise has a small cameo.
 * Troyan Bellisario, who plays Sara McGee, is a half-sibling to Sean Murray, who plays Timothy McGee, her character's brother, in NCIS. A third sibling, Michael, had a recurring role on the show but shared no scenes with either sibling. All three actors also appeared on JAG, though in different roles, and producer Donald P. Bellisario is their father. Nepotism much?
 * Also in NCIS, Mark Harmon's son plays young Gibbs.
 * In Castle, Esposito and Castle (Jon Huertas and Nathan Fillion respectively) have been teasing Ryan (Seamus Dever) about his girlfriend, who up to this point has been The Ghost. At the end of "The Mistress Always Spanks Twice" she shows up, played by Dever's wife, Juliana Dever.
 * In Oz, resident Manipulative Bastard Ryan O'Reily (played by Dean Winters) and his mentally retarded older brother Cyril O'Reily (Scott William Winters) are brothers in real life.
 * Their eldest brother, Bradford Winters, was series creator/head writer Tom Fontana's main collaborator for most of the series' run, as well.
 * On FlashForward, John Cho's wife Kerri had a small guest role as a waitress.
 * Skins has the obvious example of real life twins Kathryn and Megan Prescott playing the twins Emily and Katie, respectively.
 * And the significantly less obvious example of Effy's mum (Morwenna Banks) cheating on her screen husband (Harry Enfield) with her real one (David Baddiel).
 * Ian Lithgow, the son of John Lithgow, played one of Dick's students in 3rd Rock from the Sun.
 * Alton Brown frequently has members of his family make appearances on Good Eats. While most of his on-air family is portrayed by actors or members of the production crew, his late grandmother, mother, and daughter Zoey did make appearances as themselves. On a recent episode, Zoey Brown appeared as Alton's granddaughter which is humorous because she was effectively playing her own daughter (Zoey being Alton's only child).
 * Marlo Thomas' 1960s sitcom That Girl had Danny Thomas in a brief cameo as a priest, just so she could call him "father".
 * Mystery Science Theater 3000, at the end of its Laserblast episode, had Trace Bealieu's father in a brief cameo as an extremely-aged Dr. Forrester.
 * Peter Barlow, the repeatedly Other Darrined son of William Roache's character Ken Barlow in Coronation Street, was briefly played by Roache's son Linus in the 1970s. Linus Roache returned to the Street in 2010, now playing a completely different son, long-lost Lawrence Cunningham. Lawrence's son is played by Linus's brother, James. And James Roache also appeared in the docudrama The Road To Coronation Street, as a young William Roache!
 * The Scrubs episode "My Unicorn" had John Bennett Perry as the Patient of the Week and his son Matthew Perry as the patient's son.  That episode also cameoed Matthew's cousin Anthony as "Old Murray".
 * Thirtysomething had married couple Ken Olin and Patricia Wettig, playing the respective spouses of the other two central characters. They later play a couple in Brothers & Sisters.
 * In one episode of The Golden Girls, Bea Arthur's own adopted son plays a firefighter.
 * In Kulderzipken, King Jozef and his sister Saint-Lutgardis are played by real-life sibling Jan and Reinhilde Decleir.
 * On Terriers, Hank's sister Stephanie is played by Donal Logue's sister Karina.
 * Bud Bundy's little brother made several appearances on Married... with Children.
 * In the Dutch sitcom Het Zonnetje in Huis, father Piet Bovenkerk and son Eric Bovenkerk are played by real-life father and son John Kraaykamp and John Kraaykamp jr.
 * John Cleese and Connie Booth were married when they wrote and played in the first series of Fawlty Towers, in 1975. They were divorced by the time of the second series in 1979, but this doesn't appear to have hindered the quality of the show in any way.
 * A story arc in Ninja Sentai Kakuranger involved Jiraiya/Ninja Black, who is played by Kane Kosugi, being forced to challenge his sensei-turned-nemesis Gali, who was played by Kane's actual father Sho Kosugi.
 * Michael C. Hall and Jennifer Carpenter play brother and sister in Dexter, but were married in real life. They have since divorced.
 * Wil Wheaton's siblings Jeremy and Amy played a couple of the children in the Star Trek: The Next Generation episode "When the Bough Breaks". (Mason and Tara, respectively, if you were curious.)
 * The A-Team had an episode entitled "Bounty" in which Murdock fell in love with a vet named Kelly. Kelly was played by Wendy Fulton, who is still to this day married to Dwight Schultz and has been since 1983.
 * On The Closer, Brenda's niece Charlie was played in several episodes by Kyra Sedgewick's real-life daughter, Sosie Bacon.
 * On Primeval, Connor and Abby are played by actors who are currently engaged in real life. James Lester and Christine Johnson are also married in real life.
 * On Home Improvement, the actress who plays Jill's sister Carrie is married to Richard Karn, who plays Al.
 * In The X-Files episode "Hollywood A.D.", a movie is made based on Mulder and Scully's lives as paranormal FBI agents. Tea Leoni is cast as the movie version of Scully, and it is mentioned (jokingly) that she has a crush on Mulder. Tea Leoni being David Duchovny's wife, obviously. Of course, David Duchovny also wrote and directed that episode...
 * In the season 3 premiere of Leverage, Nate The inmate is played by Edwin Hodge, brother of Aldis Hodge, who plays Hardison.
 * The 90s series Brotherly Love was pretty much contrived for brothers Joey, Matthew and Andrew Lawrence to play themselves.
 * In The Amazing Race's 13th season, Phil's father waited for the racers at the pit stop in New Zealand, which happened to be at his ranch.
 * In The Shield, Vic Mackey's daughter Cassidy is played by Michael Chiklis's real life daughter Autumn Chiklis.
 * Marg Helgenberger's now ex-husband appeared in two episodes of CSI.
 * Chris Masterson appeared on his brother Danny’s series That '70s Show as an unrelated character. They also played brothers on one episode of White Collar.
 * Ali Marsh plays a recurring role as a psychiatrist on In Plain Sight, which stars her husband Frederick Weller. Bonus points because their characters went on a date once, but she wasn't interested.
 * Gimmie A Break: During the last three seasons, Matthew Lawrence joined his older brother, Joey, as Joey's (the character) little brother, Matt.
 * In Dad's Army, Pike's girlfriend Ivy was played by Ian Lavender's real-life wife. Arthur Lowe's wife, Joan Cooper, The Other Darrin also took over the role of Dolly Godfrey towards the end of the series.

Pro Wrestling

 * Happens often enough in Professional Wrestling that it has its own page: Wrestling Family.
 * Also the Hardys. I'm not sure about any relatives aside from that and the families in the above link.
 * There's the Briscoe Brothers, who aren't related to the Brisco Brothers but are legit brothers themselves.

Radio

 * Husband-and-wife teams were remarkably common in the golden age of radio, probably due to the number of radio acts that originated on vaudeville where family acts were common. Notable husband-and-wife radio teams include:
 * Jim and Marion Jordan (Fibber McGee and Molly)
 * George Burns and Gracie Allen
 * Jack Benny and Mary Livingstone
 * Goodman and Jane Ace (the Easy Aces)
 * Fred Allen and Portland Hoffa (Town Hall Tonight)
 * Ben Lyon and Bebe Daniels (Life With The Lyons) on The BBC at the same period.
 * In the 1990s, Jeremy Hardy and his then wife Kit Hollerbach in Unnatural Acts, later titled At Home With The Hardys in imitation of the above.
 * In the Big Finish Doctor Who story "An Earthly Child", McGann's real-life son guest-stars as the Doctor's great-grandson.

Theater

 * Many high school musicals will use the younger siblings of cast members to fill children's parts, mostly because it cuts down on scheduling issues. If one child can make it to all of the rehearsals, chances are their sibling can as well. Of course, sometimes the younger child is very good in their own right, and may even have a substantially bigger part than their brother or sister.

Video Games

 * The ending in the Japanese version of Metal Gear Solid 4: Guns of the Patriots featured Akio Ohtsuka as Solid Snake and.
 * Likewise, the Japanese release of Kingdom Hearts: Birth By Sleep uses the immediately-above same two actors for plot relevance; with Akio Ohtsuka having voiced Xehanort in the entire Kingdom Hearts series by that point, it was only natural to cast

Web Original

 * Linkara does this a lot—not surprising, since as an Internet reviewer he can't exactly afford to hire people on a regular basis. Thus far, he's utilized his parents, brother, and girlfriend at various points. (As examples: his father as an older version of him; his mother as a Starfleet commander; and his girlfriend as... herself, more or less.)
 * Doug Walker's brother is The Other Guy (Rob Walker), who mostly works behind the camera, but does appear on screen as various characters on occasion.
 * Scott McClure, the aspiring filmmaker behind The Joker Blogs, also uses this, probably for the same reasons as Linkara.

Western Animation

 * On American Dad, Rachael MacFarlane, voice actor for Hayley, is the sister of series co-creator (and voice actor for Stan and Roger) Seth MacFarlane.
 * She's also done a number of additional voices on Family Guy, including Stewie's love interest Olivia (Stewie is voiced by Seth).
 * On Dr. Katz, Professional Therapist, Laura Silverman and H. Jon Benjamin (respectively, surly secretary Laura and Ben, the 24 year old slacker son of Dr. Katz who repeatedly and unsuccessfully asks out Laura) were dating when the show started, but broke up during the middle of the show's run.
 * Mike Farrell and Shelly Fabares, who play the Kents in Superman: The Animated Series and Justice League, are married in real life.
 * The late Wayne Allwine and Russi Taylor, the voice actors of Mickey and Minnie Mouse respectively, were married until Wayne's death.
 * French voices of Homer and Marge in The Simpsons (Veronique Augereau and Philippe Peytieu) are real life spouses.
 * Alvin and The Chipmunks: Ross Bagdasarian Jr. and Janice Karman.
 * In Inspector Gadget, whenever Frank Welker wasn't available Dr. Claw was instead voiced by Don Francks, father of Cree Summer who voiced Penny.
 * Marceline's father in Adventure Time is voiced by her voice actor's (Olivia Olson) real father (Martin Olson).
 * Recess: In the episode "The Dude", Mr. Dudicoff is played by Joey Lawrence, and his little brother, Andrew Lawrence, was the voice of T.J. from 1998 to 2001.
 * In the Lilo & Stitch crossover episode (from 2005, four years after the show ended and two years after the Direct to Video movies), Gus was replaced by Zach Ewing, due to his previous voice actor, Courtland Mead, going through puberty. Zach's older brother, Blake Ewing, was the voice of Menlo in the show (He also did the singing voices for Gus and T.J. in the credits of Recess: School's Out).
 * On Bob's Burgers, the Pesto Twins are voiced by sisters Sarah and Laura Silverman.