Sister Act stars an American actress.
Kathy Ann Najimy ( born February 6 , 1957 ) is an American actress and comedian . Sister Act . Featuring musical arrangements by Marc Shaiman , the film stars Whoopi Goldberg as a Reno lounge singer who has been put under protective custody in a San Francisco convent of Poor Clares and has to pretend to be a nun when a mob boss puts her on his hit list . Also in the cast are Maggie Smith , Kathy Najimy , Wendy Makkena , Mary Wickes , and Harvey Keitel . Caryn Elaine Johnson ( born November 13 , 1955 ) , known professionally as Whoopi Goldberg ( [ ˈwhʊpi ] ) , is an American actress , comedian , author and television host .