- Rod Cameron
- Agent Rex Bennett
- Roland Got
- Agent Chang Sing
- Constance Worth
- Agent Vivian Marsh
- Nino Pipitone
- Oyama Haruchi
- Noel Cravat
- Ranga
- George J. Lewis
- Lugo
- Maxine Doyle
- Marie [Ch. 8]
- Donald Kirke
- Muller - Pier 17 Thug [Ch.1]
- Ivan Miller
- Pier 17 Customs Inspector [Ch.1]
- Walter Fenner
- Williams - Financial Agent [Ch.1]
- C. Montague Shaw
- Prof. Nicholson [Ch. 3-4]
- Harry Burns
- Tony Mills [Ch. 4, 12-13]
- Forbes Murray
- James Kennedy [Ch. 12]
- Hooper Atchley
- Harrison J. Caldwell [Ch. 5]
- Robert Homans
- Capt. Gorman [Ch. 12-13]
- Allen Jung
- Fuji - Escaped Japanese Spy [Ch.2]
- Mary Bayless
- Nurse-Receptionist
- Sam Bernard
- Karl
- Virginia Carroll
- Room Nurse
- Edmund Cobb
- Stewart
- Bill Cody
- Henchman
- John Daheim
- Balcony Thug
- Arvon Dale
- Test Pilot
- George DeNormand
- Tall Haruchi Bodyguard
- Eddie Dew
- Agent Z-24
- Martin Faust
- Lumber Mill Thug
- Charles Flynn
- Interceptor Pilot
- William Forrest
- Prof. Jackson
- Dick French
- Airport Thug
- Paul Fung
- Japanese Sub Captain
- Bud Geary
- Paint Factory Thug
- Lawrence Grant
- Sir John Brookfield
- John Hamilton
- Raymond Martin
- Kenneth Harlan
- Lab Guard / Officer Casey (uncredited)
- John James
- Boulder Dam Radio Dispatcher
- Edward Keane
- Gordon
- Charles La Torre
- Curio Shop Proprietor
- Walter Lowe
- Graham
- George Lynn
- Pilot Thug
- Otto Metzetti
- Henchman
- Hans Moebus
- Clerk
- Norman Nesbitt
- Radio Newscaster
- Pat O'Malley
- Gibson
- Eddie Parker
- Phony Butler
- Ray Parsons
- Jones
- Gil Perkins
- Mansion Heavy 1 / Intern 2 (uncredited)
- Charles Phillips
- Medium Haruchi Bodyguard
- Eddie Phillips
- Laundry Clerk Thug
- Stanley Price
- Gabby Gibbs
- John Rice
- Doorman
- Tom Seidel
- Agent Spencer
- Tom Steele
- Garage Thug / Ambulance Intern (uncredited)
- Robert Strange
- German Sub Crewman
- Elliott Sullivan
- Turner
- Harry Tauvera
- Japanese Sub Crewmen
- Duke Taylor
- Mansion Heavy 2 / Truck Heavy (uncredited)
- Ken Terrell
- Garage Thug / Yacht Thug / Explosives Thug / Warehouse Thug (uncredited)
- Dale Van Sickel
- Pier Thug
- John Wallace
- Old News Vendor
- Crane Whitley
- Dale Burnell
- Norman Willis
- German Sub Captain
- Bud Wolfe
- Consolidated Warehouse Thug
