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