- Rin Tin Tin Jr.
- Pal - Frank's Dog
- George J. Lewis
- Bob Whitlock
- Boots Mallory
- Irene Courtney - aka Irene Blane
- Frankie Darro
- Frank Courtney
- Hale Hamilton
- Norman Bryan
- Henry B. Walthall
- Jim Courtney
- Niles Welch
- Mason
- Donald Reed
- Swanson
- Gordon De Main
- Murphy
- Stanley Blystone
- Lang
- Tom London
- Brooks
- Fred Kohler
- Joe Stevens
- Yakima Canutt
- Bill [Ch. 1]
- Cornelius Keefe
- Jerry Patton [Ch. 1]
- Sarah Padden
- Mrs. Stevens [Ch. 1]
- Max Wagner
- Dave Harmon
- Lionel Backus
- Jack
- Horace B. Carpenter
- Cafe Cook [Ch. 6]
- Lane Chandler
- Ship's Mate Thompson / Police Dispatcher [Ch. 11] (uncredited)
- Kernan Cripps
- Police Captain [Chs. 11, 12]
- Leon Holmes
- Napoleon [Ch. 9]
- Jack Kenny
- Henchman
- George Magrill
- Pete
- Lafe McKee
- Dr. Smith - Veterinarian [Chs. 6, 8]
- Lew Meehan
- Rancher
- Dickie Moore
- The Boy at Airport [Ch. 1]
- Harry Northrup
- Capt. James Bethel
- Carroll Nye
- Radio Announcer [Ch. 1]
- Harry Tenbrook
- Sailor
- Wes Warner
- Cab Driver
