Once a Sinner
- År: 1950
- Land: United Kingdom
- Genre: Drama
- Studio: John Argyle Productions, Butcher's Film Service
- Nyckelord: british noir, embezzlement, bank clerk
- Direktör: Lewis Gilbert
- Kasta: Pat Kirkwood, Jack Watling, Joy Shelton, Sydney Tafler, Thora Hird, Humphrey Lestocq