Bud Abbott
Cuthbert Greenway / Dr. Ralph Greenway

Lou Costello
Horatio Prim

Marjorie Reynolds
Melody Allen

Binnie Barnes
Mildred Dean

John Shelton
Sheldon Gage

Gale Sondergaard
Emily

Lynn Baggett
June Prescott

Jess Barker
Thomas Danbury

Ann Gillis
Nora O'Leary

Donald MacBride
Lt. Mason

William Hall
Sgt. Conners

Robert Barrat
Maj. Putnam

Rex Lease
Sgt. Makepeace

Kirk Alyn
Dandy at Party (uncredited)

George M. Carleton
Museum Guard (uncredited)

Wheaton Chambers
Bill - Museum Guard (uncredited)

John Crawford
Dandy at Party (uncredited)

Vernon Downing
Leigh - Traitor (uncredited)

Marjorie Eaton
Bessie - Danbury's Maid (uncredited)

Myron Healey
Dandy at Party (uncredited)

Boyd Irwin
Cranwell - Traitor (uncredited)

Selmer Jackson
Mr. Dibbs - Museum Curator (uncredited)

William H. O'Brien
Danbury Servant (uncredited)