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)

Cordy Clark

Giggling Girl (uncredited)

Roydon Clark

Sailor (uncredited)

Sayre Dearing

Passerby/Naval Officer at Meeting (uncredited)

George DeNormand

Nazi Officer (uncredited)

Dan Dowling

Naval Officer at Meeting (uncredited)

Harold Dyrenforth

U-Boat Captain (uncredited)

Louie Elias

Sailor (uncredited)

Lisabeth Field

Miss Barnes (uncredited)

Logan Field

Lieutenant (uncredited)

Fred Fisher

Officer at Fleet Admiral's Meeting (uncredited)

Walter Friedel

Nazi Officer (uncredited)

George Golden

Naval Officer at Fleet Admiral Meeting (uncredited)

Marv Goux

Nazi Officer (uncredited)

John Hale

Sailor (uncredited)

Sam Harris

Officer at Fleet Admiral's Briefing (uncredited)

George Holmes

Scientist (uncredited)

Joseph La Cava

Officer at Fleet Admiral's Briefing (uncredited)

Mike Lally

Naval Officer at Meeting (uncredited)

Harold Miller

Officer at Fleet Admiral's Briefing (uncredited)

Charles Morton

Boat Captain (uncredited)

Henry Norell

Sailor (uncredited)

Jack Pepper

Sport Fishmern (uncredited)

Montie Plyler

Helmsman (uncredited)

Felix Reinsch

Submarine Captain (uncredited)

Waclaw Rekwart

Passerby (uncredited)

Heinz Sadler

Sonar Man (uncredited)

Scott Seaton

Old Man in Shipping Office (uncredited)

Jack Shea

Sailor (uncredited)

John Truax

Policeman (uncredited)

Edward Wermel

Scientist (uncredited)

Feridun Çölgeçen

Scientist (uncredited)

Peter Adams

Lieutenant (uncredited)