In the days of the old West, Catherine (Cat) Ballou (Jane Fonda) takes the train home, after finishing school. She does her best to appear proper, but peeks at potboilers about the notorious Kid Shelleen inside her book. On the train, she meets escaping cattle rustler Clay Boone (Michael Callan) and his uncle Jed (Dwayne Hickman). She is attracted to Clay, but not interested in becoming involved with a criminal. Cat is angry and upset when she gets home and sees that her father (John Marley) is being pressured to give up his land. He is killed by hired gun Tim Strawn. When her father's ranch hand, an Indian named Jackson (Tom Nardini) and Clay and Jed are not brave enough to help her fight back, she sends for Kid Shelleen (Lee Marvin). Kid arrives, a hopeless drunk. But they help him pull himself together, and they get their revenge. Cat is captured and sentenced to be hung, but is saved at the last minute by her friends.