- Ralph Byrd
- Dick Tracy
- Kay Hughes
- Gwen Andrews
- Smiley Burnette
- Mike McGurk
- Lee Van Atta
- Junior
- John Picorri
- Moloch
- Carleton Young
- Gordon Tracy, After
- Fred Hamilton
- Steve Lockwood
- Francis X. Bushman
- Chief Clive Anderson
- John Dilson
- Ellery Brewster [Chs. 1, 12]
- Richard Beach
- Gordon Tracy, Before [Chs. 1, 12]
- Wedgwood Nowell
- H.T. Clayton [Chs. 8-9]
- Theodore Lorch
- Patorno [Chs. 1, 12]
- Edwin Stanley
- Walter Odette
- Harrison Greene
- Cloggerstein / Durston
- Herbert Weber
- Tony Martino [Ch. 1]
- Buddy Roosevelt
- Whitney Burke
- George DeNormand
- Henchman Flynn [Chs. 2-3, 5] / Claude Destino [Chs. 6, 8-9] (as George De Normand)
- Byron Foulger
- Korvitch [Chs. 1, 12]
- Ed 'Oscar' Platt
- Oscar [Ch. 5, 6, 9, 14]
- Lou Fulton
- Elmer [Ch. 5, 6, 9, 14]
- Ann Ainslee
- Betty Clayton
- Harry Anderson
- Pete
- Roy Barcroft
- Wing Air Crewman
- Brooks Benedict
- Wing Pilot
- John Bradford
- Joe
- John Butler
- Mr. Noble
- Burr Caruth
- Mr. Wickland
- Jack Cheatham
- Agent at Floral Truck
- André Cheron
- M. Clare Renee
- Jim Corey
- Orderly-Thug
- Kernan Cripps
- Police Sergeant-Dispatcher
- Leander De Cordova
- Stevens
- Harold DeGarro
- Stilt Walker
- Lester Dorr
- Mr. Perry
- Al Ferguson
- John Henderson
- Alice Fleming
- Orphange Matron
- Sam Flint
- Meeting Chairman
- Sidney Friedlander
- Little Boy
- Jack Gardner
- Necklace Thief / G-Man (uncredited)
- Roscoe Gerald
- Power Co. Watchman-Thug
- Kit Guard
- Farley
- Henry Hale
- Dirigible ZQR6 Radioman
- John Holland
- Anderson's Secretary
- William Hopper
- Dirigible Pilot
- William Humphrey
- Mr. James
- Jack Ingram
- Reporter
- I. Stanford Jolley
- Roadside Thug / G-Man / Reporter / Intern (uncredited)
- Jane Keckley
- Old Mrs. Henkin
- Mary Kelley
- Georgetta Clarabelle
- Jack Kenney
- Reporter
- Donald Kerr
- Reporter
- Edward LeSaint
- Governor
- Walter Long
- Whitey
- Wilfred Lucas
- Mr. Vance
- Eva McKenzie
- Teacher
- Bruce Mitchell
- Cmdr. Brandon
- Monte Montague
- Clancy Fosse
- Milburn Morante
- Death Valley Johnny
- Louis Morrell
- Walter Potter
- Forbes Murray
- Henry Coulter
- Nicholas Nelson
- Puppeteer
- Kitty O'Neil
- Orphanage Matron [Ch. 1]
- Gene Otis
- Little Boy
- Charles Phillips
- Reporter
- Hal Price
- Joe Crane
- Spencer Quinn
- Little Boy
- Lorin Raker
- Tony
- Bob Reeves
- Officer
- Loren Riebe
- Hanger / Diner Thug (uncredited)
- William Stahl
- Agent at Floral Truck
- Jack Stewart
- Motorcycle Cop
- Harry Strang
- Bill Moffett
- Henry Sylvester
- Dirigible Commander
- Al Taylor
- Henchman Costain
- John Ward
- Doctor
- Wally West
- J. Kraft
- Buddy Williams
- Bootblack
