Feisty Irishman Finian McLonergan (Fred Astaire) and his faithful daughter, Sharon (Petula Clark), bearing a pot of gold stolen from the leprechaun Og (Tommy Steele), settle in the village of Rainbow Valley, Missitucky. Siding with local sharecroppers like Woody Mahoney (Don Francks) against a blustering, bigoted local politician (Keenan Wynn), the McLonergans get into a number of fanciful scrapes while being pursued by the magical Og, who will become mortal if he doesn't recover his gold.