Don Knotts
Role: Henry Limpet
Carole Cook
Role: Bessie Limpet
Jack Weston
Role: George Stickel
Andrew Duggan
Role: Harlock
Larry Keating
Role: Admiral P.P. Spewter
Oscar Beregi Jr.
Role: Nazi Admiral (as Oscar Beregi)
Charles Meredith
Role: Fleet Admiral
Elizabeth MacRae
Role: Ladyfish (voice)
Paul Frees
Role: Crusty (voice)
Wesley Gale
Role: Man Staring Into Window (uncredited)
Leon Alton
Role: Officer at Fleet Admiral's Meeting (uncredited)
Phil Arnold
Role: Short Fisherman (uncredited)
George Bruggeman
Role: Nazi Officer (uncredited)
Paul Busch
Role: Sonar Man (uncredited)
Al Checco
Role: Sailor (uncredited)
Cordy Clark
Role: Giggling Girl (uncredited)
Roydon Clark
Role: Sailor (uncredited)
Sayre Dearing
Role: Passerby/Naval Officer at Meeting (uncredited)
George DeNormand
Role: Nazi Officer (uncredited)
Dan Dowling
Role: Naval Officer at Meeting (uncredited)
Harold Dyrenforth
Role: U-Boat Captain (uncredited)
Louie Elias
Role: Sailor (uncredited)
Lisabeth Field
Role: Miss Barnes (uncredited)
Logan Field
Role: Lieutenant (uncredited)
Fred Fisher
Role: Officer at Fleet Admiral's Meeting (uncredited)
Walter Friedel
Role: Nazi Officer (uncredited)
George Golden
Role: Naval Officer at Fleet Admiral Meeting (uncredited)
Marv Goux
Role: Nazi Officer (uncredited)
John Hale
Role: Sailor (uncredited)
Sam Harris
Role: Officer at Fleet Admiral's Briefing (uncredited)
George Holmes
Role: Scientist (uncredited)
Joseph La Cava
Role: Officer at Fleet Admiral's Briefing (uncredited)
Mike Lally
Role: Naval Officer at Meeting (uncredited)
Harold Miller
Role: Officer at Fleet Admiral's Briefing (uncredited)
Charles Morton
Role: Boat Captain (uncredited)
Henry Norell
Role: Sailor (uncredited)
Jack Pepper
Role: Sport Fishmern (uncredited)
Montie Plyler
Role: Helmsman (uncredited)
Felix Reinsch
Role: Submarine Captain (uncredited)
Waclaw Rekwart
Role: Passerby (uncredited)
Heinz Sadler
Role: Sonar Man (uncredited)
Scott Seaton
Role: Old Man in Shipping Office (uncredited)
Jack Shea
Role: Sailor (uncredited)
John Truax
Role: Policeman (uncredited)
Edward Wermel
Role: Scientist (uncredited)
Feridun Çölgeçen
Role: Scientist (uncredited)
Peter Adams
Role: Lieutenant (uncredited)
