The Mysterons / Colonel White / Captain Black (voice)
Captain White / Captain Black
Colonel White / Captain Black / Mysteron Voice
Polly's Husband (uncredited)
Inspector Wills
Extra (uncredited)
Captain Ross
Headmaster
Col. George Gordon
Robert Maitland
TV Program Announcer (uncredited)
Jimmy Thompson
William Peck
Stukely
Peter Burroughs
Ted Fleming
James Martin
Albert de Courcey
Young Yacht Guest (uncredited)
Don (as Eldred Tidbury)