Charlie
Chief of Police
Muirhead
Lawrence Watkins
Niagara Clerk
Johnson
Professor Caligostro
Newell Morse
Skinner
George Dunlap
John J. Oldham
Professor (archive footage) (uncredited)
Hotel Clerk
reporter Virgil Whitaker
John C. Allyn
Mike Forrester
Hughie Sprague
Truman Hardy
Dudley Stone
Charles B. Horsley
Windy
Speed
Sergeant McLeash
Steve Wilson
Patsy
Chuck Haskins
Dr. Carver
Himself
Kipp
Charlie Rickenbacker
Niki's Orderly