Richard Dix as John Sinclair / John Carter

Lynn Merrick as Joan Martin Sinclair

Rhys Williams as Ernie Sparrow

James Cardwell as Fred (Doc) Graham

Tom Kennedy as Ferdinand / Hammerlock

Sam Ash as Gibson Motor Car Co. Executive (uncredited)

Egon Brecher as Dr. Rose (replaced by Frank Reicher) (uncredited)

Charles Coleman as Sinclair's Butler (uncredited)

Otto Forrest as The Whistler (uncredited)

Byron Foulger as Georgie (uncredited)

Martín Garralaga as Tony, Fruit Peddler (uncredited)

John Hamilton as Doctor (uncredited)

Stuart Holmes as Sinclair Executive (uncredited)

Wilbur Mack as Sinclair Executive (uncredited)

Charles Marsh as Sinclair Executive (uncredited)

Harold Miller as Sinclair Executive (uncredited)

Forbes Murray as Sinclair Executive (uncredited)

Gigi Perreau as Bobbie (uncredited)

Frank Reicher as Dr. Rose (uncredited)

Clinton Rosemond as Train Porter (uncredited)

Frank J. Scannell as Druggist (uncredited)

Minerva Urecal as Georgie's Wife (uncredited)

Robert B. Williams as Pharmacist (uncredited)

Douglas Wood as Paul Kitridge - Attorney (uncredited)