Waco is a Western film that focuses on a small Wyoming town in chaos. The townspeople ask Mayor Ned West (Robert Lowery) to bring in outside help after Sheriff Billy Kelly (Richard Arlen) is shot. The mayor arranges for Waco (Howard Keel), a gunfighter, to be released from jail to come help the town. Almost as soon as he arrives, Waco is able to clean up the town, even becoming the sheriff. He enlists the help of his former partner, Ace Ross (Brian Donlevy) to help keep the town in order. Jill Stone (Jane Russell) is the wife of Preacher Sam Stone (Wendell Corey) and the former lover of Waco. She is one of the few residents that is not pleased about Waco's arrival. Eventually, trouble finds its way back to town, causing Waco and the townsfolk to become involved in a gunfight that causes casualties and leaves Waco's life forever changed.