Key Witness
- Blwyddyn: 1947
- Gwlad: United States of America
- Genre: Crime, Drama, Thriller
- Stiwdio: Columbia Pictures
- Allweddair: inventor, film noir, murder, corpse
- Cyfarwyddwr: D. Ross Lederman
- Cast: John Beal, Trudy Marshall, Jimmy Lloyd, Helen Mowery, Wilton Graff, Barbara Read