It stars Kirk Douglas as cowboy Jack Burns, Gena Rowlands as his best friend's wife, and Walter Matthau as a sheriff who sympathises with Burns but must do his job and chase him down. It also featured an early score by legendary composer Jerry Goldsmith. Douglas felt that this was his favorite film.
John W. "Jack" Burns (Kirk Douglas) works as a roaming ranch hand much as the cowboys of the old West did, refusing to join modern society. He rejects much of modern technology, not even carrying any identification such as a driver's license or draft card. He can't provide an address because he just sleeps wherever he finds a place.
As Burns crosses a highway into a town in New Mexico, his horse Whiskey has a difficult time crossing the road, confused and scared by the traffic. They enter town to visit Jerry (Gena Rowlands). She is the wife of an old friend, Paul Bondi (Michael Kane), who has been jailed for giving aid to illegal immigrants. Jack explains his dislike for a society that restricts a man on where he can or can't go, what he can or can't do.
After a violent barroom fight against a one-armed man (Bill Raisch) in which he chooses to use only one arm himself, Burns is arrested. When the police decide to let him go, he deliberately punches a cop to get himself arrested. He is immediately sentenced to a year in jail, which allows him to see Bondi, with a purpose of helping him escape. The town is a sleepy border town and the cops are mostly bored, occasionally dealing with minor offenses. The Sheriff, Morey Johnson (Walter Matthau), has to compel them to pay attention to their duties at times. During the course of the story, the seemingly unrelated progress of a tractor-trailer truck carrying toilets, driven by Carroll O'Connor, is inter-cut with the principal events.
Joining Bondi in jail, Burns tries to persuade him to escape. He tells Bondi he couldn't spend a year in jail because he'd probably kill someone. Burns defends Bondi from the attention of sadistic Deputy Sheriff Gutierrez (George Kennedy), and the deputy picks Burns as his next target. During the night they saw through one of the jail's bars using two hacksaw blades Burns hid in his boot. The deputy summons Burns from his cell in the middle of the night and beats him. Upon returning to his cell, Burns tries to persuade Bondi to join him in escaping, but Bondi has a family and too much at stake to become a fugitive from the law, so he refuses to go. Burns breaks out by himself and returns to Bondi's house where he picks up his horse and some food from Bondi's wife. After the jail break, the Sheriff learns that Burns served in the military during the Korean War, including 7 months in a disciplinary training center for striking a superior officer. He also received a Purple Heart and a Distinguished Service Cross with oak leaf clusters for his valor during battle.
Burns heads for the mountains on horseback with the goal of crossing the border into Mexico. The police mount an extensive search, with Sheriff Johnson and his Deputy Sheriff Harry (William Schallert) following him in a jeep. A military helicopter is brought in to help find Burns. When the air crew locates Burns, they relay his location to the Sheriff and attempt to bring Burns in. Whiskey is repeatedly spooked by the helicopter and other modern noises. Burns shoots the tail rotor of the aircraft, damaging it and causing the pilot to lose control and crash land.
Deputy Gutierrez also chases Burns. He sees Burn's horse and thinks he has Burns fixed in place. He is preparing to shoot him when Burns sneaks up on him and disarms him, knocking him unconscious with the his rifle butt. Burns leads his horse up impossibly difficult, steep, rocky slopes to escape his pursuers, but the lawmen keep on his trail, forcing him to keep moving. Surrounded on three sides by lawmen closing in, his horse refuses at first to climb a steep slope. They finally surmount the crest of the Sandia Mountains and escape into the east side of the mountains, a broad stand of heavy timber, with the lawmen, including Deputy Gutierrez, shooting at him. The Sheriff acknowledges that Burns has evaded their attempts to capture him. Burns is shot through the ankle during his dash to the timber.
Burns appears to have escaped the law and his trackers late at night when he tries to cross Highway 66 in Tijeras Canyon during a heavy rainstorm. His horse is spooked, confused by noise of the traffic and blinded by the lights. The truck driver hauling the load of toilets, his vision obscured by rain, strikes Burns and his horse as they are attempting to cross the road. The sheriff arrives and, asked if Burns is the man he has been looking for, says he can't identify him, because he's never seen the man he is looking for up close. Whiskey, who is seriously wounded, is killed by Harry with a gunshot. The Sheriff and his deputy Harry head home; Burns is transported from the scene in an ambulance. The film closes with a shot of Burn's cowboy hat swamped by rain in the middle of the highway.
In the film, the river of traffic—Highway 66 by name—serves as bookends. Early in the yarn, Burns crossed the highway horseback, with difficulty, to enter the town. Saddled up in Old West tradition, entering a modern town, the rider crossed a dangerous boundary—a Rubicon of sorts—that says “There’s no going back, no escape.” In the ending, still on horseback, he tries to cross that highway again.
- Kirk Douglas as John W. "Jack" Burns
- Gena Rowlands as Jerry Bondi
- Walter Matthau as Sheriff Morey Johnson
- The horse as Whiskey
- Michael Kane as Paul Bondi
- Carroll O'Connor as Truck Driver
- William Schallert as Harry (Johnson's deputy)
- George Kennedy as Gutierrez (sadistic deputy)
- Karl Swenson as Rev. Hoskins (prison inmate)
- Dan Sheridan as Deputy Glynn
- Bill Raisch as the one-armed man
It happens to be a point of view I love. This is what attracted me to the story – the difficulty of being an individual today.
Douglas assembled the cast and crew through his production company, Joel Productions, recruiting ex-blacklisted writer Dalton Trumbo, who had written Spartacus several years before, to write the screenplay.
The working title for the film was "The Last Hero," but the release title of the film was a matter of contention between Douglas, who wanted to call it "The Brave Cowboy" after the novel, and the studio. Douglas wanted the film to open in art houses and build an audience, but Universal chose to market the film as a Western, titling it "Lonely Are the Brave" and opening it widely without any particular support. Despite this, the film has a cult following, and is often listed as one of the best Westerns ever made.
Miller crafted the picture with a reverence and eloquent feeling for the landscape, complimenting the story's depiction of a lone and principled individual tested by tragedy and the drive of his fiercely independent conscience.
The score to Lonely Are the Brave was composed and conducted by Jerry Goldsmith. Goldsmith's involvement in the picture was the result of a recommendation by veteran composer Alfred Newman who had been impressed with Goldsmith’s score on the television show Thriller and took it upon himself to recommend Goldsmith to the head of Universal Pictures’ music department, despite having never met him.
- Bill Bixby has a small part as an airman in a helicopter, his first film appearance.
- This is one of the first film appearances of Carroll O'Connor (TV's All in the Family)
- Bill Raisch is the one-armed man who fights with Douglas in a memorable scene. The following year Raisch began menacing David Janssen in the classic TV series The Fugitive.
Kirk Douglas was nominated for a 1963 BAFTA Award as "Best Foreign Actor" for his work in Lonely Are the Brave, and placed third in the Laurel Awards for "Top Action Performance". The Motion Picture Sound Editors, USA gave the film a "Golden Reel Award" for "Best Sound Editing" (Waldon O. Watson, Frank H. Wilkinson, James R. Alexander, James Curtis, Arthur B. Smith), in a tie with Mutiny on the Bounty.
- Jerry Bondi (Gena Rowlands): "Believe you me, if it didn't take men to make babies I wouldn't have anything to do with any of you!" 
- Jack Burns (Kirk Douglas): "Know what a loner is? He's a born cripple. He's a cripple because the only person he can live with is himself. It's his life, the way he wants to live. It's all for him. A guy like that, he'd kill a woman like you. Because he couldn't love you, not the way you are loved." 
- Jack Burns: "A westerner likes open country. That means he's got to hate fences. And the more fences there are, the more he hates them." Jerry Bondi: "I've never heard such nonsense in my life." Jack Burns: "It's true, though. Have you ever noticed how many fences there're getting to be? And the signs they got on them: no hunting, no hiking, no admission, no trespassing, private property, closed area, start moving, go away, get lost, drop dead! Do you know what I mean?" 
- Jack Burns: "I don't need [identification] cards to figure out who I am, I already know."  This line was used by the fugitive sailor in "The Death Ship," the 1927(?) Novel by B. Traven.