William Powell
— Andrew Gentling
Shelley Winters
— Catherine Sykes
Marsha Hunt
— Martha Wier
Dorothy Hart
— Helen Gentling
James Gleason
— Captain Gledhill
Felix Bressart
— Professor Morris Avrum
Art Baker
— Henry Pritchard
Sheldon Leonard
— Detective Pacciano
Howard Freeman
— Dr. Markheim
Houseley Stevenson
— Montgomery Thatcher
Paul Harvey
— Mr. Arnspiger
Francis Pierlot
— Dr. Herbert Watson
Jess Barker
— Arnold Sykes
Mikel Conrad
— Freddie Blair
Vangie Beilby
— Old Lady at Lecture (uncredited)
Marjorie Bennett
— Waitress (uncredited)
Leonard Bremen
— Truck Driver (uncredited)
Paul Brinegar
— Reporter (uncredited)
Frank Cady
— Reporter (uncredited)
Edmund Cobb
— Policeman (uncredited)
Helen Crozier
— Maid (uncredited)
Johnny Duncan
— Bellhop (uncredited)
Adolph Faylauer
— Bald Man at Lecture (uncredited)
Sandra Gould
— Newspaper Girl (uncredited)
Ethyl May Halls
— Woman at Window (uncredited)
Chuck Hamilton
— Policeman (uncredited)
Herbert Heywood
— Attendant (uncredited)
Tommy Ivo
— Horace - Boy at Roadblock (uncredited)
Lyle Latell
— Reporter (uncredited)
George Lynn
— Policeman (uncredited)