In the gay '90s, cardsharps take over a Mississippi riverboat from a kindly captain. Their first act is to change the showboat into a floating gambling house. A ham actor and his bumbling sidekick try to devise a way to help the captain regain ownership of the vessel.

In Fox's contribution to the all-star revue cycle of early talkies, showboat singer Margie, hearing that the show is in arrears, goes to New York to gather all of the former stars to stage a minstrel show as a benefit.