Gene Evans

Steve Karnes

André Morell

Prof. James Bickford

Leigh Madison

Jean Trevethan

John Turner

John

Alastair Hunter

Dr. C. A. Morris, the village doctor

Lloyd Lamble

Senior Admiral, at the Admiralty

Jack MacGowran

Dr. Sampson, the paleontologist

Maurice Kaufmann

Mini Submarine Officer

Henri Vidon

Tom Trevethan

Patrick Jordan

Photo Lab Aide

Howard Lang

Naval Commader, at the "Valkyrie" wreck (uncredited)

Leonard Sachs

Dialogue Scientist at Conference (bit)

Ernest Blyth

Scientist at Conference (uncredited)

Neal Arden

TV Newscaster (uncredited)

Paul Beradi

Man Listening to Car Radio (uncredited)