Don 'Red' Barry

Mike O'Hara, "King Cobra"

Sheila Ryan

Janet 'J.L.' Brannigan

Tom Brown

Joe O'Hara

Joseph Crehan

Oscar Brannigan

John Cason

Tiger Johnson

William Edmunds

Professor Berger

Margia Dean

Joy White

Lyle Talbot

Radio Announcer

Michael Vallon

Bettor

Sam Flint

Doctor

Chester Clute

Timid Man

Jack Perry

Trainer (uncredited)

Noble 'Kid' Chissell

Fight Spectator (uncredited)

Charles Morton

Fight Spectator (uncredited)

Sol Murgi

Fight Spectator (uncredited)

Stanley Price

Fight Spectator (uncredited)

Harvey Parry

Bit Role (uncredited)

Al Bain

Fight Spectator (uncredited)