Sister Act is a 1992 American musical crime comedy film directed by Emile Ardolino and written by Paul Rudnick (billed as Joseph Howard). It stars Whoopi Goldberg as a lounge singer forced to join a convent after being placed in a witness protection program. It also features Maggie Smith, Kathy Najimy, Wendy Makkena, Mary Wickes, and Harvey Keitel.

Sister Act was one of the most financially successful comedies of the early 1990s, grossing $231 million worldwide against a $31 million budget. Its success extended to the home video market, and it was the most rented film of 1993 in the United States. The film spawned a franchise, which consists of the 1993 sequel Sister Act 2: Back in the Habit and a musical adaptation, which premiered in 2006. A third film is in development for Disney+.