Little Orphan Annie runs away from her abusive guardian with her dog Sandy. She meets Johnny Adams, a friendly truck driver who gives her a lift, and during the drive, reveals his dream of being a champion fighter. Johnny is fired for picking up Annie, but promises to meet her in New York. In the city, Annie and Sandy find shelter in a warehouse in a tenement district. The warehouse guard, Pop Corrigan, a former fight trainer, lets her stay on, and by month's end, the warehouse is Annie's home. Annie's cheerful and helpful spirit endears her to her tenement neighbors, and she stands up for them when they are attacked by loan shark Spot McGee because they are unable to repay their debts. Annie attends a local boxing match with her friend, Mary Ellen, and discovers that Johnny is in the ring. He is badly beaten, and she brings him home to the warehouse. Pop undertakes Johnny's training, which the neighbors pay for without the young man's knowledge. They hope that Johnny will win a professional match, the prize of which they would use to repay McGee. With the help of one of Pop's friends, Johnny is booked for a professional match at Lewis Stadium, and he falls in love with Mary Ellen during the course of his training. When Mary Ellen's father, Tom Jennings, is attacked by McGee's thugs, Monk and Hutch, Johnny comes to his rescue, further inspiring the support of the neighbors. Johnny and Annie protest when his match is cancelled, and their cause becomes headline news: "Robin Hood pugilist fights for entire tenement district." Fight promoter Val Lewis reschedules Johnny's match against Dude Dawson. When Johnny is unable to come up with the thousand dollars to pay for the match, neighbor Soo Long sells the coffin for which he has saved his entire life, and gives Johnny the money. McGee tries to sabotage Johnny's chances of winning by locking him and Annie in their gym, but the women of the tenements hear their shouts and, after beating up on McGee's thugs, free Johnny. He arrives at the stadium just in time to fight the match and bests Dawson in the ring. Annie splits the winnings, giving half to the neighborhood for a mutual aid society, and the other half to Johnny and Mary Ellen for their honeymoon.