- John 'Dusty' King
- Ace Drummond
- Jean Rogers
- Peggy Trainor
- Noah Beery Jr.
- Jerry
- Guy Bates Post
- The Grand Lama
- Lon Chaney Jr.
- Ivan - Henchman
- Jackie Morrow
- Billy Meredith
- Robert Warwick
- Winston
- James B. Leong
- Henry Kee [Chs. 1-11]
- Chester Gan
- Kai-Chek
- Arthur Loft
- Chang-Ho / The Dragon
- James Eagles
- Johnny Wong - Radio Operator
- C. Montague Shaw
- Dr. Trainor
- Frederik Vogeding
- Bauer [Chs. 1-6]
- Al Bridge
- Paul Wyckoff
- Hooper Atchley
- Caldoni
- Edmund Cobb
- Nicolai - Henchman
- Sam Ash
- Le Page
- Stanley Blystone
- Sergei - Henchman
- George DeNormand
- Henchman
- Diana Gibson
- Stewardess
- Lew Hicks
- Minor Role
- Selmer Jackson
- William Meredith Sr.
- Eddie Parker
- O'Connor - Co-Pilot [Ch. 1] / Mongolian Henchman [Ch. 1] / Car Driver [Ch. 4] / Dimitri - Cave Henchman [Chs. 7-8, 10] / Sedan Bearer [Ch. 10] (uncredited)
- Edward Peil Sr.
- Queen of India Plane Passenger [Ch. 1]
- House Peters Jr.
- Pete - Second Pilot [Ch. 1] / Clipper Pilot [Ch. 8] (uncredited)
- Dewey Skipworth
- Sedan Bearer
- Tom Steele
- Henchman
- Kam Tong
- Mongolian Worker
- Louis Vincenot
- Lotan [Chs. 1-3]
- Russell Wade
- Second Co-Pilot
- Dick Wessel
- Boris - Henchman
