Spaceship to the Unknown

Buster Crabbe

— Flash Gordon (archive footage)

Jean Rogers

— Dale Arden (archive footage)

Frank Shannon

— Dr. Hans Zarkov (archive footage)

Charles Middleton

— Ming the Merciless (archive footage)

Priscilla Lawson

— Princess Aura (archive footage)

Richard Alexander

— Prince Barin (archive footage)

Jack 'Tiny' Lipson

— King Vultan (archive footage)

James Pierce

— Prince Thun (archive footage)

Earl Askam

— Officer Torch (archive footage)

Richard Tucker

— Prof. Gordon (archive footage)

George Cleveland

— Prof. Henson (archive footage)

Lon Poff

— The High Priest (archive footage)

Charles McMurphy

— Atom Furnace supervisor (archive footage)

Theodore Lorch

— Priest #2 (archive footage)

Duke York

— (scenes deleted) (archive footage) (as Duke York Jr.)

Lynton Brent

— Transcontinental airplane pilot (archive footage) (uncredited)

Al Ferguson

— Telescreen monitor (archive footage) (uncredited)

Fred Kohler Jr.

— Robot / Ming soldier (archive footage) (uncredited)

Bull Montana

— Monkey-Man (archive footage) (uncredited)

Constantine Romanoff

— Monkey-Man (archive footage) (uncredited)

Glenn Strange

— Robot / Ming soldier / Gocko (archive footage) (uncredited)

Harry Wilson

— Captured soldier (archive footage) (uncredited)