Don Knotts

Henry Limpet

Carole Cook

Bessie Limpet

Jack Weston

George Stickel

Andrew Duggan

Harlock

Larry Keating

Admiral P.P. Spewter

Oscar Beregi Jr.

Nazi Admiral (as Oscar Beregi)

Charles Meredith

Fleet Admiral

Elizabeth MacRae

Ladyfish (voice)

Paul Frees

Crusty (voice)

Wesley Gale

Man Staring Into Window (uncredited)

Leon Alton

Officer at Fleet Admiral's Meeting (uncredited)

Phil Arnold

Short Fisherman (uncredited)

George Bruggeman

Nazi Officer (uncredited)

Paul Busch

Sonar Man (uncredited)

Al Checco

Sailor (uncredited)