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)

Max Faulkner

PLA Radio Operator (uncredited)

Neil Hallett

Dr. Sampson's Helicopter Pilot (uncredited)

André Maranne

French Radio Officer (uncredited)

Derren Nesbitt

The Radar Operator, at the radar room (uncredited)

Guy Standeven

Naval Officer in Situation Room (uncredited)