Richard Dix
John Sinclair / John Carter
Lynn Merrick
Joan Martin Sinclair
Rhys Williams
Ernie Sparrow
James Cardwell
Fred (Doc) Graham
Tom Kennedy
Ferdinand / Hammerlock
Sam Ash
Gibson Motor Car Co. Executive (uncredited)
Egon Brecher
Dr. Rose (replaced by Frank Reicher) (uncredited)
Charles Coleman
Sinclair's Butler (uncredited)
Otto Forrest
The Whistler (uncredited)
Byron Foulger
Georgie (uncredited)
