Finian McLonergan and his daughter, Sharon, immigrate from Ireland to the mythical state of Missitucky, USA. Finian has brought with him a crock of gold to plant in the soil near Fort Knox so it will grow and make him wealthy. However, the leprechaun, Og, follows Finian to America because he wants his gold back. While in America, Finian and Sharon are introduced to the horrors of racism. Accidentally, because she is standing over the magically buried crock, Sharon transforms a racist senator into a black man. In the end, however, all is well. The Senator learns tolerance, Sharon falls in love with a landowner and even Og finds love in the landowner’s mute sister.