Who Done It?

Bud Abbott

Chick Larkin

Lou Costello

Mervin Q. Milgrim

Patric Knowles

Jim Turner

Louise Allbritton

Jane Little

Mary Wickes

Juliet Collins

William Gargan

Detective Inspector Lou

William Bendix

Detective Sgt. Brannigan

Thomas Gomez

Col. J.R. Andrews

Ludwig Stössel

Dr. Anton Marek

Edmund MacDonald

'Murder at Midnight' Announcer

Jerome Cowan

Heller

Walter Tetley

'Shorty', a studio pageboy

Joe Kirk

Harry, 'Murder At Midnight' sound man

Don Porter

'Murder at Midnight' program manager

Norman Abbott

'Murder at Midnight' Organist

Abel Pina

Acrobat (uncredited)