Key Witness
- Año: 1947
- País: United States of America
- Género: Crimen, Drama, Suspense
- Estudio: Columbia Pictures
- Palabra clave: inventor, film noir, murder, corpse
- Director: D. Ross Lederman
- Emitir: John Beal, Trudy Marshall, Jimmy Lloyd, Helen Mowery, Wilton Graff, Barbara Read