In addition to the show's regular cast of voice actors, celebrity guest stars have been a staple of The Simpsons, an American animated television sitcom created by Matt Groening for the Fox Broadcasting Company, since its first season.
The family was initially conceived by Groening for a series of animated shorts, which originally aired as a part of The Tracey Ullman Show between 1987 and 1989.
Guest voices have come from a wide range of professions, including actors, athletes, authors, musicians, artists, politicians and scientists.
Several guest stars have featured as recurring characters on the show, including Phil Hartman, Joe Mantegna and Kelsey Grammer.
Three guest stars, Ricky Gervais, Seth Rogen and Pete Holmes, earned writing credits for the episodes in which they appeared.
Guest stars have appeared on The Simpsons since its first season, in addition to the show's main cast of Dan Castellaneta, Julie Kavner, Nancy Cartwright, Yeardley Smith, Hank Azaria and Harry Shearer and supporting cast of Tress MacNeille, Maggie Roswell, Chris Edgerly, Dawnn Lewis, Grey DeLisle, Alex Désert, Jenny Yokobori, Kimberly D. Brooks, Tony Rodríguez and Jonathan Lipow and former supporting cast members Jo Ann Harris, Russi Taylor, Christopher Collins, Susan Blu, Lona Williams, Doris Grau, Marcia Mitzman Gaven, Karl Wiedergott, Melanie Minchino, Eric Lopez and Pamela Hayden.
[4] Other repeat guest stars include Albert Brooks, Glenn Close, Jan Hooks, Maurice LaMarche, Jon Lovitz, Jane Kaczmarek, Jackie Mason, Charles Napier and Frank Welker.
"[8] Bill Oakley and Josh Weinstein, showrunners of the seventh and eight seasons, favored guest stars with what they felt were unique and interesting voices such as actors R. Lee Ermey, Donald Sutherland, Kirk Douglas and Lawrence Tierney.
[16][17] Other people to turn the show down include actors Michael Caine,[18] Tom Cruise,[19] Clint Eastwood and Anthony Hopkins[20] and director Quentin Tarantino.
Musician Frank Zappa and actor Anthony Perkins both became too ill to record their parts,[20][23] while Jim Carrey had to drop out due to time constraints,[24] and Faye Dunaway cancelled.
Robby Krieger of The Doors recorded a cameo for the episode "The Great Money Caper", but his part was cut because the writers felt his appearance seemed too forced.
[26] Similarly, actress Catherine O'Hara recorded the voice of Colette the waitress in "Flaming Moe's", but was redubbed with Jo Ann Harris who the producers felt was a better fit.
Mason, Grammer and Anne Hathaway have each won the Primetime Emmy Award for Outstanding Voice-Over Performance for their guest voice roles on the show.
Additionally, executive producer Matt Selman stated that he has a part in mind for Larry David for an upcoming episode but has doubts whether he'll accept the offer.
Beyond the television series and the movie, there have been other media products of The Simpsons where guest stars have provided vocal talents in addition to the regular cast.