Voice of the Whistler

John Sinclair / John Carter

Joan Martin Sinclair

Ernie Sparrow

Fred (Doc) Graham

Ferdinand / Hammerlock

Gibson Motor Car Co. Executive (uncredited)

Dr. Rose (replaced by Frank Reicher) (uncredited)

Sinclair's Butler (uncredited)

The Whistler (uncredited)

Georgie (uncredited)

Tony, Fruit Peddler (uncredited)

Doctor (uncredited)

Sinclair Executive (uncredited)

Sinclair Executive (uncredited)

Sinclair Executive (uncredited)

Sinclair Executive (uncredited)

Sinclair Executive (uncredited)

Bobbie (uncredited)

Dr. Rose (uncredited)

Train Porter (uncredited)

Druggist (uncredited)

Georgie's Wife (uncredited)

Pharmacist (uncredited)

Paul Kitridge - Attorney (uncredited)