Kind-hearted, fatherly John Chisum (John Wayne) owns a large ranch in Lincoln County, New Mexico, in the 1870s. With the help of his faithful sidekick, Pepper (Ben Johnson), and a hot-headed young ranch hand nicknamed Billy the Kid (Geoffrey Deuel), Chisum does battle with underhanded land developer Lawrence Murphy (Forrest Tucker). Having bought up most of the nearby town and appointed his own corrupt sheriff (Bruce Cabot), Murphy now has his eye on Chisum's ranch.