Frank Buck

Frank Hardy

Sasha Siemel

Tiger Van Dorn

Reginald Denny

Ralph Marshall

Esther Ralston

Valerie Shields

Charlotte Henry

Dorothy Elliott

William Bakewell

Tom Banning

Clarence Muse

Lightning

Willie Fung

Chiang-Houseboy

LeRoy Mason

Jim Murphy

Matthew Betz

Inspector Starrett

Richard Tucker

Robert Banning

Duncan Renaldo

Armand Roget

Fred Kohler Jr.

John Charles

Sherwood Bailey

Paul Marshall

Harry 'Snub' Pollard

Campbell

George Rosener

Professor

Gertrude Sutton

Mrs. Maitland

John St. Polis

Chandler Elliott

John Davidson

Doctor Coleman

Milburn Morante

Singapore Joe

Dirk Thane

Joe Nolan

Robert Warwick

Angus MacLeod

Dahlam Ali

Hardy's Assistant

Jim Corey

Henchman

Paul Ellis

Greenway

Henry Hale

Jackson

Harry Harvey

Roget Clerk #1

Reed Howes

Sailor

Jack Ingram

Undercover Detective at Dive

Tom London

Detective Interrogating Pete

Merrill McCormick

Peters

Blackie Whiteford

Henchman

Roger Williams

Henchman