Cat Ballou is a 1965 American western comedy film starring Jane Fonda and Lee Marvin, who won an Academy Award for Best Actor for his dual role. The story involves a woman who hires a notorious gunman to protect her father's ranch, and later to avenge his murder, only to find that the gunman is not what she expected. The supporting cast features Tom Nardini, Michael Callan, Dwayne Hickman, and Nat King Cole and Stubby Kaye, who together perform the film's theme song, and who appear throughout the film in the form of travelling minstrels or troubadours as a kind of musical Greek chorus and framing device.
 The film was directed by Elliot Silverstein from a screenplay by Walter Newman and Frank Pierson adapted from the 1956 novel The Ballad of Cat Ballou by Roy Chanslor, who also wrote the novel filmed as Johnny Guitar. Chanslor's novel was a serious Western, and though it was turned into a comedy for the film, the filmmakers retained some darker elements. The film references many classic Western films, notably Shane. The film was selected by the American Film Institute as the 10th greatest Western of all time in its AFI's 10 Top 10 list in 2008.
 Catherine "Cat" Ballou, a notorious outlaw, is set to be executed in the small town of Wolf City, Wyoming. Two banjo and guitar playing "Shouters", Professor Sam the Shade and the Sunrise Kid, sing the ballad of Cat Ballou and regale the audience with the tale of how she began her career of crime.
 Some months prior, Catherine, then an aspiring schoolteacher, is returning home by train to Wolf City from finishing school. On the way, she unwittingly helps accused cattle rustler Clay Boone elude his captor, Sheriff Maledon, when Boone's Uncle Jed, disguised as a preacher, distracts the lawman.
 Arriving home at her father (Frankie Ballou)'s ranch, Catherine learns that the Wolf City Development Corporation is scheming to take his ranch. Frankie's sole defender is his ranch hand, educated Native American, Jackson Two-Bears. Clay and Jed appear and reluctantly offer to help Catherine. She hires legendary gunfighter Kid Shelleen to help protect her father from gunslinger Tim Strawn, the tin-nosed hired killer who is threatening him.
 Shelleen arrives and proves to be a drunken bum who is a crack shot only when he is inebriated. His presence proves to be useless as Strawn abruptly kills Frankie. When the townspeople refuse to bring Strawn to justice, Catherine becomes a revenge-seeking outlaw known as Cat Ballou. She and her gang rob a train carrying the Wolf City payroll, then take refuge in the desperado hideout "Hole-in-the-Wall". Shelleen is shocked to discover the legendary outlaw Cassidy is now a humble saloonkeeper in Hole-in-the-Wall. 
 The gang is thrown out when it is learned what they have done, due to Hole-in-the-Wall's continued existence being dependent on the sufferance of Wolf City. Strawn arrives and threatens Cat. Shelleen, motivated by his affection for Cat, works himself into shape. Dressed up in his finest gunfighter outfit, he goes into town and kills Strawn, then reveals he is Strawn's brother.
 Cat poses as a prostitute and confronts Sir Harry Percival, the head of the Wolf City Development Corporation. She attempts to force him into confessing that he ordered her father's murder. A struggle ensues; Sir Harry is killed, and Cat is sentenced to be hanged. With Sir Harry dead,  Wolf City's future is hopeless, and the townspeople have no mercy for Cat. As the noose is placed around her neck, Uncle Jed, again disguised as a preacher, appears and cuts the rope just as the trapdoor opens. Cat safely falls through and onto a wagon, and her gang spirits her away in a daring rescue.
 Cast notes
 The film was director Elliot Silverstein's second feature film, with the pressure of filming leading to some quarrels with the producer Harold Hecht, although the film was ultimately a box office success.
 Ann-Margret was the first choice for the title role, but her manager turned it down without letting the actress know.[why?] Ann-Margret wrote in her autobiography that she would have taken the part. Among others, Kirk Douglas allegedly turned down the role of Shelleen. Years later, he played a similar double role in The Man from Snowy River.
 Nat King Cole was ill with lung cancer during the filming of Cat Ballou. A chain smoker, Cole died four months before the film was released.
 Jay C. Flippen suffered a circulatory failure during filming and, as a result, later had his leg amputated due to gangrene.
 The film was well received by critics. It earned over $20.6 million in North America, making it the 7th highest-grossing film of 1965.
 Bosley Crowther of The New York Times called it "a breezy little film" which "does have flashes of good satiric wit. But, under Elliott Silverstein's direction, it is mostly just juvenile lampoon." Variety wrote that the film "emerges middlingly successful, sparked by an amusing way-out approach and some sparkling performances." Richard L. Coe of The Washington Post praised the film as a "springy satire", adding, "What makes this fun is the style. Forming a mighty cool duo, Nat King Cole and Stubby Kaye sing their way in and out of the plot with folk songs which Cole 'Don't Fence Me In' Porter would have relished. The format is novel and stylishly delivered." Pauline Kael in Film Quarterly called it "lumpen, coy, and obvious, a self-consciously cute movie," adding that "mainly it is full of sort-of-funny and trying-to-be-funny ideas and a movie is not just ideas." Philip K. Scheuer of the Los Angeles Times wrote, "I'm in the minority, apparently. Cat Ballou, which is being hailed as a cowboy Tom Jones or something of the sort, seems to me about as funny as a soundtrack burp." The Monthly Film Bulletin wrote, "The jokes in Cat Ballou are uneven, but the mood behind the film is happily consistent."
 The film holds a score of 90% on Rotten Tomatoes based on 29 reviews, with an average grade of 7.4 out of 10.
 In his Oscar acceptance speech, Lee Marvin concluded by saying, "I think, though, that half of this belongs to a horse somewhere out in San Fernando Valley," a reference to the horse Kid Shelleen rode, which appeared to be as drunk as Shelleen was.
 Two separate television pilots were filmed. A 1970 pilot written and produced by Aaron Ruben featured Lesley Ann Warren as Cat, Jack Elam as Kid Shelleen and Tom Nardini repeating his role while a 1971 pilot starred Jo Ann Harris as Cat, Forrest Tucker as Kid Shelleen and Lee J. Casey as Jackson Two-Bears.