In 1877, Bounty Hunter Major Marquis Warren is transporting three dead bounties to the town of Red Rock, Wyoming. He hitches a ride on a stagecoach driven by O.B. Jackson. Aboard is bounty hunter John Ruth, and handcuffed to him is fugitive Daisy Domergue, whom Ruth is escorting to Red Rock to collect her bounty and watch her hang. Ruth and Warren are previous acquaintances, having had dinner once together, who bonded over Warren's personal letter from Abraham Lincoln. Former Lost-Causer militiaman Chris Mannix, who is traveling to Red Rock as the town's new sheriff, persuades Ruth and Warren to let him on the stagecoach. Warren and Ruth form an alliance to protect each other's bounties.
The group seeks refuge from a blizzard at Minnie's Haberdashery, a stagecoach lodge, whose front door happens to have a broken lock. They are greeted by Bob, a Mexican, who says the owner, Minnie, is away visiting her mother. The other lodgers are Oswaldo Mobray, an English hangman; Joe Gage, a quiet cowboy traveling home to visit his mother; and Sanford Smithers, a former Confederate general traveling to put his son to rest. Suspicious, Ruth disarms all but Warren. Warren inadvertently kicks a jellybean resting on the floor between the slats, and then notices one of Minnie's jellybean jars is missing from a shelf.
As the group eats, Mannix surmises that Warren's Lincoln letter is a forgery. Warren acknowledges this, saying the letter buys him leeway with whites, outraging Ruth. Warren leaves a gun next to Smithers and provokes him into reaching for it by telling Smithers that he tortured, raped, and murdered Smithers' son. When Smithers pulls the gun, Warren shoots him out of revenge for Smithers' executions of black PoWs at the Battle of Baton Rouge.
While everyone is distracted by the confrontation, someone poisons the brewing coffee. Ruth and Jackson drink it, killing Jackson. The dying Ruth attacks Daisy in desperation, but she kills him with his own gun. Warren disarms Daisy, leaving her shackled to Ruth's corpse, and holds the others at gunpoint. He is joined by Mannix, whom Warren trusts because he nearly drank the poisoned coffee himself. After finding Sweet Dave's chair stained with blood and claiming that Minnie hates Mexicans and would never leave one to care for the lodge, Warren deduces that Bob is an impostor who killed the lodge owners and executes him. When Warren threatens to execute Daisy, Gage admits that he poisoned the coffee. A man hiding in the cellar shoots Warren in the genitals. Mobray draws a concealed gun and shoots Mannix, who returns fire, wounding Mobray.
Hours earlier, Bob, Mobray, Gage, and a fourth man, Daisy's brother Jody, arrive at the lodge. They murder Minnie, and five other bystanders, leaving only Smithers. Jody tells Smithers that they plan to ambush Ruth to rescue Daisy, and that his gang will spare Smithers if he keeps quiet. During the murders, a jar of jellybeans is shattered, and the lock on the front door is destroyed. The bandits dispose of the bodies, hide the evidence, and conceal guns around the lodge. As Ruth's stagecoach arrives, Jody hides in the cellar.
In the present, Mannix and Warren, both seriously wounded, hold Daisy, Gage, and the dying Mobray at gunpoint. They force Jody out of the cellar by threatening to kill Daisy. Jody surrenders and Warren executes him. Daisy claims that fifteen of her brother's men are waiting in Red Rock to kill Mannix and ransack the town; if Mannix kills Warren and allows her to escape, the gang will spare him and let him claim the bounties of the deceased except her brother.
As Daisy and Mobray taunt Warren, Warren shoots them both, mortally wounding Mobray. Gage draws a hidden revolver, but is shot dead by Mannix and Warren. Warren then tries to shoot Daisy, but he is out of bullets. Mannix calls Daisy's bluff and rejects her offer, but faints from blood loss. Daisy hacks off Ruth's handcuffed arm and frees herself. As she reaches for Gage's gun, Mannix regains consciousness, shooting her. Warren persuades Mannix to hang her from the rafters inside the lodge in honor of Ruth. Afterward, as the two men lie dying, Mannix reads aloud Warren's forged Lincoln letter.
