Leo Gorcey as Muggs McGinnis

Bobby Jordan as Danny Breslin

Huntz Hall as Limpy

Warren Hull as Officer Tom Brady

Charlotte Henry as Mary Breslin

Keye Luke as Clancy

Bobby Stone as Monk Martin

Donald Haines as Skinny, red-haired kid

Sunshine Sammy Morrison as Scruno

David Gorcey as PeeWee

Martha Wentworth as Mrs. Brady

Jack Mulhall as Cop at Prizefight with the Lieutenant

Eddie Foster as Slats Morrison

Dennis Moore as Dorgan

Tony Carson as Henchman Dutch

Pat Costello as Muggs' Trainer

Dick Ryan as Police Lieutenant

Bill Cartledge as Johnny Ryan, Muggs' opponent (uncredited)

Minerva Urecal as Head of Reform School (uncredited)

Jack Chefe as Henchman Nick (uncredited)

Jack Carr as Milkman George (uncredited)