Kenneth Tobey

Character: Captain Patrick Hendry

Margaret Sheridan

Character: Nikki

Robert Cornthwaite

Character: Dr. Arthur Carrington

Douglas Spencer

Character: Ned 'Scotty' Scott

James Young

Character: Lt. Eddie Dykes

Dewey Martin

Character: Crew Chief Bob

Robert Nichols

Character: Lt. Ken 'Mac' Erickson

William Self

Character: Corporal Barnes

Nicholas Byron

Character: Tex Richards

Eduard Franz

Character: Dr. Stern

George Fenneman

Character: Dr. Redding

Paul Frees

Character: Prof. Voorhees

Everett Glass

Character: Prof. Wilson

Norbert Schiller

Character: Dr. Lorenz

Edmund Breon

Character: Prof. Ambrose

John Dierkes

Character: Dr. Chapman

Sally Creighton

Character: Mrs. Chapman

James Arness

Character: 'The Thing'

David McMahon

Character: Gen. Fogarty

Bill Neff

Character: Bill Stone (uncredited)

Robert Stevenson

Character: Capt. Smith - Fogarty's Aide (uncredited)