Jack Armstrong
John Hart
Betty Fairfield
Rosemary La Planche
Princess Alura [Chs. 3-6, 9-11, 15]
Claire James
Billy Fairfield (as Joe Brown)
Joe Brown Jr.
Uncle Jim Fairfield
Pierre Watkin
Prof. Hobart Zorn
Wheeler Oakman
Henchman Blair
Jack Ingram
Henchman Slade
Eddie Parker
Vic Hardy
Hugh Prosser
Director
Wallace Fox
Screenplay
Arthur Hoerl
Leslie Swabacker
Story
George H. Plympton
Lewis Clay
Royal K. Cole