Junior G-Men

Billy Halop

Billy Barton

Huntz Hall

Gyp

Gabriel Dell

Terry

Bernard Punsly

Lug

Ken Lundy

Buck

Kenneth Howell

Harry Trent

Roger Daniel

Midge

Phillip Terry

Jim Bradford

Russell Hicks

Col. Barton

Cy Kendall

Brand

Ben Taggart

Severn

Victor Zimmerman

Henchman Corey

Edgar Edwards

Henchman Evans

Gene Rizzi

Henchman Foster

Florence Halop

Mary

Donald Curtis

Henchman Akin (uncredited)

Al Hill

Henchman Burke (uncredited)

Ralph Peters

Henchman Greeley (uncredited)

Harris Berger

Sailor (uncredited)

Hal E. Chester

Murph (uncredited)

Edward Fielding

Professor Farraday (uncredited)

George Eldredge

Draftsman Lynch (uncredited)

Bill Cartledge

Junior G-Man (uncredited)

Julie Duncan

Crawford's Secretary (uncredited)