The story follows Catherine "Cat" Ballou, a recently graduated schoolteacher who returns to her Wyoming hometown to find her father's ranch under siege by the evil Wolf City Development Corporation. Her father, Frankie Ballou, is being harassed by a notorious gunman with a silver nose named Tim Strawn, hired by the corporation to force him off his land. Determined to protect her family and home, Cat turns from a law-abiding citizen into an outlaw. She assembles a motley crew consisting of her former teacher Clay Boone, his uncle Jed, and an Indian ranch hand named Jackson Two-Bears.

In desperation, Cat hires the famous gunslinger Kid Shelleen to help defend the ranch. However, the once-legendary Kid is now a drunken wreck who can barely shoot straight. Despite his shortcomings, the ragtag group makes a valiant effort to stand up against the corrupt forces threatening their lives. As the situation intensifies, Cat finds herself poorly navigating the violent world of outlaws and gunmen, leading to a series of misadventures and confrontations that forever change her life.