as Peter Burroughs
as Ted Fleming
as Colonel White / Captain Black / The Mysterons (voice)
as Polly's Husband (uncredited)
as William Peck
as Inspector Wills
as Don (as Eldred Tidbury) (uncredited)
as Jimmy Thompson
as Captain White / Captain Black / The Mysterons (voice)
as Stukely
as Robert Maitland
as Young Yacht Guest (uncredited)
as Extra (uncredited)
as James Martin
as TV Program Announcer (uncredited)
