- Billy Lee
- Billy Freeman
- Addison Richards
- William Freeman
- Bradley Page
- Judge Roger Davis
- Kay Linaker
- Joan Allen
- Herbert Rawlinson
- David J. Titus
- Lee Phelps
- Sgt. Day
- John Berkes
- Sam Stoner
- Bryant Washburn
- Colonel of Marines
- George N. Neise
- Hans
- Donald Curtis
- Fred
- Hal Price
- Officer Sullivan
- Steve Clark
- Trainer Wilson
- Ace the Wonder Dog
- Pal - Billy's Dog
- Arch Hall Sr.
- Dispatcher
- Tom London
- Hinkel - Fifth columnist
- Pat Moran
- Trainer
