Celebrity Star

An episode of a show which departs from its usual type of plot to make the best possible use of a celebrity or major star who happens to be available, regardless of plausibility, coherence, or continuity.

If the Celebrity Star is a musician or band, they often play themselves (or a thinly veiled facsimile thereof, as on The Facts of Life) and usually have to play one of their hit songs.

Sometimes the Celebrity Star shows up to rescue a character from the consequences of a Celebrity Lie.

See Special Guest for episodes that aren't focused on the celebrity. See As Himself for works when the entire series/film is about the celebrity playing themselves.

Examples of Celebrity Star include:

This trope was what the third season of 30 Rock was based on.
On The Replacements. Voiced by Miley Cyrus, the teen pop queen is named... Celebrity Star.
Spoofed on Jimmy Neutron, when the Fake Band Grey Star showed up for Libby's birthday party. Even the time-traveling giant robot policeman was their biggest fan.

Evil Robot: Grey Star? That's my favorite retro oldies band!

Joe Namath on The Brady Bunch, among many others.
- Especially in "Getting Davy Jones," where the episode was entirely dedicated to helping Marcia get Davy Jones from The Monkees to sing at her school's 8th grade prom. He makes a very memorable appearance near the end, and even reprised his role in The Brady Bunch Movie and in the stage show, The Real Live Brady Bunch.
Nancy Reagan on a Very Special Episode of Diff'rent Strokes.
Randy Travis, Hey Arnold!!, "Mr. Hyunh Goes Country". Voiced facsimile Travis Randall, and the titular Mr. Hyunh (when singing).
Parody: Scrubs' fourth-season episode "My Life in Four Cameras" spends the middle section in a conventional-sitcom fantasy, complete with a talent show that will pay exactly as much money as the main characters need. A mild-mannered cafeteria worker enters the talent contest and turns out to be American Idol runner-up Clay Aiken. It is unclear whether the producers decided to use Clay Aiken before or after they decided to do a sitcom fantasy, but it certainly is the only way his musical act could be fit into the show.
Both The Simpsons and Futurama have done this more than once.
- Futurama parodied this trope by having the Harlem Globetrotters show up as recurring characters. They're insanely competent Omnidisciplinary Scientists who only occasionally crack wise about yo momma after seeing if you got game.
  - Also, they're from another planet.
The Doobie Brothers appeared on the 70's sitcom What's Happening to teach Rerun An Aesop about the evils of bootlegging concerts.
Kiss appeared on Family Guy in an episode focused on a series of their concerts, and integrated themselves into the Back Story. Gene Simmons and Lois had "history" from high school. And by history, I mean lots of sex.
- And, oddly, James Woods. And, even more oddly, Rush Limbaugh.
  - A lot of the quick throwaway gags actually feature people as themselves. Ted and Barney making out, Charlie saying Brian always slags them off, etc.
Degrassi the Next Generation did an entire Celebrity Star arc about Kevin Smith coming to Degrassi to make his new film, "Jay and Silent Bob Go Canadian, Eh?" The reason he appeared on the show was that Smith had a huge crush on the character Caitlin from Degrassi High (he got to be in scenes with the grown-up Caitlin, played by the same actress). Unusually, the arc actually had long-lasting effects after Smith's last episode.
Duck Dodgers did this often. Two examples are the episodes with Tom Jones (who sings the theme song) and Megadeth. In one example, Duck Dodgers uses a magical device to reach through space and time to steal Tom Jones's voice for a music contest. The Megadeth episode involved him unfreezing their guitarist and using their music to blow up a 'Saxoblivion' Death Ray. Don't ask...
Parodied in Sealab 2021, "Meet Beck Bristow." Sealab shuts down all its normal work so Hollywood Actor Beck Bristow (voiced by Hollywood Actor Brian Bloom) can come around and let everybody know that he is Hollywood Actor Beck Bristow, and therefore better than the regular characters.
Sister, Sister did this once, where the Celebrity Star turned out to be... Marques Houston, who played Roger on the show, and himself (under his "Batman" Immature/IMX name) in that particular ep.
- More conventionally, they also had WNBA star Lisa Leslie as herself twice...and they went up against the Olsen twins on a game show, among many others.
Beakman's World subverted this trope regularly. Its Celebrity Stars are all actually Famous Dead Guys (or Girls) played by the cast (generally Beakman himself, who would hang a lampshade by saying "What'd I miss?"). The show did play the trope straight twice, starring Jean Stapleton as Beakman's Mom.
Subverted in many early episodes of South Park, when celebrity guests would get to voice such prestigious roles as "Gay Dog" (George Clooney) and "Turkey #4".
King of the Hill does this from time time, but also starred musician Chuck Mangione as a semi-regular.
An episode of the Flintstones included an appearance by "Ann-Margrock", and another was a semi-crossover with the animated intro to Bewitched.
- And let's not forget Stoney Curtis, Jimmy Darrock, Stoney Carmichael, Jimmy O'Neillstone (Jimmy O'Neill was the host of the music show Shindig), etc.
Smallville does this a lot with musical guests. Whenever WB has a new album being released by a big or up and coming music group, that group will always end up in Smallville for a show, no matter how much of a stretch or departure from the main plot it is.
- In a town that houses a high-profile multibillionaire family with a tendency to pull strings and do extravagant unannounced favors for ~~their friends~~ people they're trying to impress, that's about a two-inch stretch.
  - There's also the matter of the alien teenager battling other aliens/monsters/government agents/etc. on a regular basis. An impromptu concert is probably the most normal thing to happen in that town.
Mel Torme showed up in multiple episodes of Night Court (Judge Harry was an enormous Torme fan).
- Torme also appeared in Sliders like this, but then his son was the show runner.
Similar to the above Sister, Sister example, singer Brandy Norwood appeared as herself on her own sitcom, Moesha. (A bit of a suberversion, in that one of the show's running gags was that Mo (Norwood) couldn't hold a note with both hands and a bucket).
The Kate Modern episode "I Am Hallam Foe!" consists entirely of Jamie Bell talking about how he just met Charlie, and that he thinks she's "fit". The episode is only 36 seconds long, and given the title, is probably meant as Product Placement.
Touched By an Angel did this in almost every episode, with guests ranging from Travis Tritt to Charlotte Church to Rosa Parks. Yes, Rosa Parks.
In the episode of Designing Women where Charlene has her baby, Dolly Parton appeared in a dream sequence as her "Guardian Movie Star."
- Like way too many to name, Dolly Parton has also done this on The Simpsons. On the other hand, there aren't many who've also played themselves on Alvin and The Chipmunks...
Parodied, then subverted in Extras in which Coldplay's Chris Martin appeared on Show Within a Show When The Whistle Blows as himself, inexplicably playing a musical number in the factory. Of course, Extras is itself known for including a different Celebrity Star each episode (so much so that the episodes are identified by which celebrity appears in them parodying themselves) so the whole sequence is almost certainly a deliberate self-parody.
- It's also heavily lampshaded by Gervais' characters in both Extras and the Show Within a Show "When the Whistle Blows" who repeatedly points out the ridiculousness of Chris Martin suddenly appearing in a factory in Wigan.
George Michael starred as himself, both in hallucinations and playing himself, in Eli Stone.
- Although this doesn't really fit the trope, because he's part of the Myth Arc instead of just being a one-episode guest star.
The "Comic Book Carnage" story in Hack Slash featured real horror comic creators being killed off by Loony Fans angry about their Darker and Edgier version of a fictional-within-the-story superhero.
The Middleman featured Boy Band Varsity Fanclub in one episode. Not terribly unconventional, except, that they were actually alien dictators who were intent on conquering Earth, and the episode ended with them being killed off.
Every Backyard Sports game does this after the first two. This player is the cover athlete and usually the best in the game. Of course, since the athlete is a kid, there is a different voice actor.
The Steve Harvey Show has episodes featuring Snoop Dogg, Puff Daddy (as he was known then), Lil Bow Wow, and Teddy Riley all playing themselves, but only Lil Bow Wow gave a performance. Ron Isley was also a frequent guest star, as one of the members of The Hi-Tops.
In Alice, diner-owner Mel Sharples and his waitresses seemed to know several famous people. Guest included George Burns, Telly Savalas, Jerry Reed, Dinah Shore, and Art Carney.
Whitney Houston appeared on an episode of Boston Public where she performed one of her songs at the prom.
Max Steel is complicated; it has episodes guest-starring Tony Hawk and Jeremy McGrath. As their episodes were Xtreme Sport Xcuse Plots, and series protagonist Josh McGrath was a high-level competitor who would logically be in the same circles, this doesn't seem to fit at first, until one remembers that Josh left competition because of Power Incontinence giving him an unfair advantage. These episodes take place long after the show had started focusing exclusively on Josh's secret-agent career and as such briefly go back to the athletics theme of the beginning. Matt Hoffman's episode, and Jeremy McGrath's second episode, take place at a point in the series when Josh returns to active competition and much of the show is once again taking place on the sports circuit, so they're not departures from the norm.
One of the most famous examples is the All in The Family episode "Sammy's Visit", featuring Sammy Davis, Jr.
Mark Hamill has guest starred in a few series, most notably The Simpsons and 3rd Rock from the Sun.
- Which includes some Adam Westing.
The first Daria movie, Is It Fall Yet?, featured cameos by Dave Grohl and Bif Naked. This being Daria, one of them plays a perverted blowhard who attempts to bed every woman in sight and another plies a minor with alcohol in an unsuccessful attempt to seduce her.
The premise of Call of the Dead is as follows: Dawn of the Dead director George Romero is making a zombie film, and the lead roles include Sarah Michelle Gellar (star of Buffy the Vampire Slayer), Danny Trejo (star of Machete), Robert Enguland (Freddy in A Nightmare on Elm Street) and Michael Rooker (of The Walking Dead). Then real zombies show up and the actors have to put what knowledge of horror films they have to good use... that is load up on all the guns they can find and blow the everloving crap out of anything that moves.
Phineas and Ferb loves to subvert this trope, by having celebrities show up and be given relatively minor roles. This is most obvious with their singing guests. They had Bowling for Soup, who did their theme song, come to play the extended them- except no one recognised them, 'cause they were in the future. In "Summer Belongs To You" the boys somehow managed to hire Clay Aiken and Chaka Khan for a single song. The ultimate example would be the "Family Christmas Special", where Kelly Clarkson spends the entire episode trying to sing, but Phineas keeps stopping her.