A groupie is a person whose devotion to a person (usually a celebrity, especially a rock and roll star) approaches the level of fanaticism.

Groupie is derived from group, meaning a musical band, but now has more general application.

Female groupies in particular are known for a long-standing tradition of being available for, and willing to have, sexual intercourse with celebrities and rock stars. While only a small number of groupies are truly promiscuous in that they are willing to trade sexual favors for attention, the tradition of "rock and roll groupies" continues to the present day, contributing to the image of the rock-and-roll lifestyle as one where sex and drugs are readily available at any time. Anal sex is sometimes associated with groupies.

The 1999 movie, Almost Famous, explored the lives of rock beat writers, rock and roll stars and their groupies.

The Japanese band Pizzicato Five paid homage to the groupie lifestyle in 1994 on their a track from their Japan-only album "Overdose" called If I Were A Groupie. The song originally featured vocalist Maki Nomiya singing in Japanese over a documentary recording of an American groupie recounting her exploits with glee, while a serious Japanese voice delivered a simultaneous translation. The following year the song was re-recorded (presumably for copyright reasons) for the band's second US album release "The Sound of Music by Pizzicato Five", with one of the band's US management team providing the "groupie's" spoken vocals.