Written by Leon Uris and directed by John Sturges, a famous lawman gets help from a gun-slinging gambler as he takes on criminals who refuse to obey the gun laws.
At Fort Griffin, Texas the gambler Doc Holliday (Kirk Douglas) is suffering from tuberculosis and talks with his friend Kate Fisher (Jo Van Fleet) while he throws knives into the door. She wants him to stay out of danger. Ed Bailey (Lee Van Cleef) wants to kill Holliday who shot his brother. According to Holliday, the brother had cheated at cards, was drunk, and pulled a gun on him. Sheriff Cotton Wilson (Frank Faylen) requires guns be checked in the saloon. Marshal Wyatt Earp (Burt Lancaster) rides into town and talks with Sheriff Wilson who tells him he did not detain the criminals Johnny Ringo and Ike Clanton because he is getting old even though Wyatt had sent him a telegram. Wyatt sees Bailey’s gang in the saloon, but he has no gun on him. Wyatt goes to see Holliday and warns him that Ed Bailey has a derringer in his left boot. Holliday goes to the saloon and quarrels with Ed who reaches for his pistol as Holliday pulls out a switchblade and throws it into his chest, killing him. The Sheriff arrests Holliday, but Wyatt finds he is being held in his hotel room. Wyatt knocks out the guard and goes in the room to warn Holliday a lynch mob is gathering to get him. Wyatt has arranged for Kate to be waiting with two horses behind the hotel. He signals her from the window, and she starts a fire in a hay loft. As men go to fight the fire, Holliday escapes with her.
Wyatt returns to Dodge City, Kansas where his deputy Charles Bassett (Earl Holliman) tells him that Holliday and Kate are there even though Wyatt told him to stay out of Dodge. Holliday tells Wyatt that every town has been rejecting him. Beautiful Laura Denbow (Rhonda Fleming) arrives with a trunk of French dresses. She plays poker, but Wyatt arrests her for violating the ordinance against women playing poker there. Bat Masterson asks Wyatt for his deputies to chase fugitive criminals, and Wyatt tells him to bring them back before the cowpokes arrive from a cattle drive. Holliday bets the saloon-keeper double or nothing on the $1,000 he owes him that he can bail Laura out of jail, and he manages to persuade Wyatt to let her out. Wyatt has her play cards only in a side-room. Wyatt needs deputies to chase three robbers, and Holliday agrees to go with him because Wyatt had saved his life. They camp together, and the three men attack them at night while they seem to be sleeping; but they are awake and kill the three robbers.
Doc Holliday learns that Kate left him to be with Johnny Ringo (John Ireland), but Doc refuses to have a gunfight with Ringo who insults him by splashing his drink on him. Meanwhile Wyatt helps Laura when she is out riding and has a lame horse, and they fall in love. He promises to quit being a lawman so they can get a ranch in California. Trail boss Shanghai Pierce (Ted de Corsia) leads his cowboys into town, and they shoot wildly and cause damage. When Deputy Bassett tries to collect their guns, they shoot him. Wyatt confronts them in the saloon and tells them to remove their guns. He is outnumbered, but Doc suddenly pulls his gun and grabs another for Wyatt who then forces Pierce and his men to unbuckle their gun-belts. Wounded Bassett gives Wyatt a telegram, and Wyatt has to tell Laura that he has to go help his brother Virgil who is marshal in Tombstone, Arizona. They quarrel over his broken promise and separate. Doc decides to leave town also and goes with Wyatt.
Virgil Earp (John Hudson) and his wife Betty (Joan Camden) welcome Wyatt and their brothers Morgan Earp (DeForest Kelley) and 19 year-old Jimmy Earp (Martin Milner). They discuss how to take on Ike Clanton and his brothers and the McLowerys. Wyatt goes out to the Clanton ranch and tries to persuade young Billy Clanton (Dennis Hopper) not to be a gunslinger. When Ike arrives home, he threatens Wyatt who shows him a document proving that he is now a federal marshal. The Clantons and Ringo plan to ambush Wyatt during his nightly round, and Kate is there. That night Jimmy offers to do the round for Wyatt who says he can use the sleep. When Jimmy is checking the town, about four men ride in and shoot him dead and ride out. Wyatt arranges with Ike a meeting in the morning at the OK Corral. Wyatt goes to Doc for help; but he is very sick, and Kate says he is dying. However, in the morning Doc is dressed and joins Wyatt, Virgil, and Morgan. They are facing Ike Clanton, his brother Billy, Tom McLowery (Jack Elam), and three others. Cotton Wilson does not want to fight with him this time; when he tries to ride off during the gun-fight, the Clantons shoot him. During the gun battle Virgil and Morgan are wounded, and Doc kills Ringo. All six of their adversaries are killed. Wyatt does not want to kill Billy, but Doc shoots him before he can shoot Wyatt.
This version of the famous gunfight is fictionalized. The actual gunfight took less than a minute, and only Billy Clanton and Tom and Frank McLowery were killed. Ike Clanton and Billy Claiborne fled from the flight. Ike filed murder charges against the Earps and Holliday, but they were exonerated by a local judge and a grand jury. This story emphasizes the different values of the lawman Wyatt Earp and the gambling Doc, but by helping each other they became friends. One of the ways the law officers tried to check the gun violence then was to require people to remove their guns in town.