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)

Al Checco

Sailor (uncredited)

Sayre Dearing

Passerby/Naval Officer at Meeting (uncredited)

George DeNormand

Nazi Officer (uncredited)

Harold Dyrenforth

U-Boat Captain (uncredited)

Louie Elias

Sailor (uncredited)

George Golden

Naval Officer at Fleet Admiral Meeting (uncredited)

Sam Harris

Officer at Fleet Admiral's Briefing (uncredited)

George Holmes

Scientist (uncredited)

Mike Lally

Naval Officer at Meeting (uncredited)

Harold Miller

Officer at Fleet Admiral's Briefing (uncredited)

Charles Morton

Boat Captain (uncredited)

Scott Seaton

Old Man in Shipping Office (uncredited)

Jack Shea

Sailor (uncredited)