Sister Act is a 1992 American comedy film directed by Emile Ardolino and written by Joseph Howard. The film stars Whoopi Goldberg as Deloris Van Cartier, a Reno lounge singer who witnesses her mobster boyfriend, Vince LaRocca (played by Harvey Keitel), commit murder. Deloris goes to the police, but they can't protect her since Vince has friends in high places, so they arrange to hide her in a convent until the trial.
Despite initial resistance from the Mother Superior (played by Maggie Smith), Deloris adapts to life in the convent and helps rejuvenate the church's struggling choir. Along the way she becomes close with her fellow nuns, including Sister Mary Patrick (Kathy Najimy), Sister Mary Robert (Wendy Makkena), and the quiet but sweet Sister Mary Clarence (Mary Wickes).
As the choir begins to gain attention, eventually performing for a mass with the archbishop in attendance, Deloris becomes a beloved member of the community, teaching the nuns about music and dance. However, Vince finds out about Deloris's whereabouts from a mole in the police department and sends his men to the convent to kill her during the choir's performance.
In the final act of the film, the nuns defend themselves and Deloris from the hitmen, using their newfound confidence and skills to defeat them. The police arrive and arrest Vince, while Deloris decides to stay at the convent to continue helping the community.
Sister Act was a critical and commercial success, grossing over $230 million worldwide. It also spawned a sequel, Sister Act 2: Back in the Habit, released in 1993.