When a brash Reno lounge singer named Deloris Van Cartier witnesses a mob hit, her life takes a divinely unexpected turn. Placed in protective custody by a weary police lieutenant, she is hidden in the one place no one would think to look: a struggling San Francisco convent. Under the stern gaze of the formidable Mother Superior, played by Maggie Smith, Deloris, portrayed by the irrepressible Whoopi Goldberg, is forced to disguise herself as a nun. Her irreverent spirit and love for soulful music immediately clash with the convent's quiet, traditional ways.

Tasked with whipping the chaotic choir into shape, Deloris—now Sister Mary Clarence—injects a hefty dose of Motown rhythm and showbiz flair into their hymns. Her unorthodox methods, aided by the enthusiastic Sister Mary Patrick (Kathy Najimy) and the shy Sister Mary Robert (Wendy Makkena), unexpectedly transform the choir into a local sensation, filling the pews and saving the parish. However, as her newfound fame threatens to blow her cover, Deloris must navigate the growing suspicions of Mother Superior and the relentless pursuit of her gangster boyfriend (Harvey Keitel), all while discovering an unexpected sense of community and purpose within the convent walls. This hilarious and heartwarming comedy proves that sometimes, the most unlikely sanctuary can lead to the most joyful redemption.