Behemoth, the Sea Monster

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

H

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

Leonard Sachs Dialogue Scientist at Conference (bit)