S.O.S. Metaluna

Rex Reason

as Dr. Cal Meacham

Faith Domergue

as Dr. Ruth Adams

Jeff Morrow

as Exeter

Lance Fuller

as Brack

Robert Nichols

as Joe Wilson

Russell Johnson

as Steve Carlson

Douglas Spencer

as The Monitor of Metaluna

Karl Ludwig Lindt

as Dr. Adolph Engelborg

Regis Parton

as Mutant (uncredited)

Richard Deacon

as Pilot (uncredited)

Coleman Francis

as Express Deliveryman (uncredited)

Robert B. Williams

as Webb (uncredited)

Charlotte Alpert

as Metaluna Woman at Decompression Console (uncredited)

Spencer Chan

as Dr. Hu Ling Tang (uncredited)

Lizalotta Valesca

as Dr. Marie Pitchner (uncredited)