The film starts at an underground fight circuit. Carter Ford (Post Malone) is dominating in the ring, and a bar owner named Frankie (Jessica Williams) has her eyes on him. After Carter beats his opponent, another fighter, Elwood Dalton (Jake Gyllenhaal), enters the ring. Carter recognizes him and refuses to fight, which means Dalton still gets the money without having to fight.
Outside, a guy stabs Dalton after he lost 500 bucks from the fight, but once he sees that Dalton is barely fazed, the guy starts running. Frankie approaches Dalton as he tends to his wound, saying she runs a road house bar, actually called “The Road House” in a Floridian community, Glass Key. She offers Dalton a chance to work for her as a bouncer. While he initially doesn’t seem keen on joining, he eventually accepts since he has no other options in life.
Dalton arrives in Glass Key. He meets a teenage book store owner named Charlie (Hannah Lanier) and her father Stephen (Kevin Carroll). They give Dalton a free book and direct him to the Road House. He arrives and meets employees Billy (Lukas Gage) and Laura (B.K. Cannon) before getting to work.
At night, Dalton watches as Billy and the other male employees have to handle rowdy guys. Moments later, a biker gang led by Dell (JD Pardo) arrives and begins to torment the staff and patrons. Dalton calmly attempts to speak to Dell, but he only antagonizes Dalton. He steps outside towards the gang’s bikes to lure them out before egging Dell on. He threatens to kill Dalton until the man smacks him and proceeds to knock all the bikers down. Dalton then drives the gang to the hospital himself. On his way out, he is chastised by a doctor named Ellie (Daniela Melchior) for bringing them there since they take up priority from more deserving patients. After he charms her, she tends to his wounds.
Dalton sleeps in a boat on the lake where Frankie warns him there is a crocodile living nearby. As he sleeps, Dalton dreams about his last round as a UFC fighter.
Dell and his goons arrive on a yacht owned by crime boss Ben Brandt (Billy Magnussen), whom they work for. They inform him about Dalton and how he mopped the floor with them. Brandt orders them to get rid of him by any means necessary, as he sees Dalton as a threat to his business in town.
Dalton soon finds that the locals quickly know who he is, and other thugs back off when they see him. He mentors Billy and the other guys on how to handle belligerent patrons. Dalton points out one guy that has a concealed knife, and he disarms him before kicking him out.
After a night of work, Dalton starts to walk home when Dell and his goons attempt to run him over in Dell’s girlfriend’s truck. They manage to knock Dalton off the bridge, but he survives. When he gets home, he finds Dell waiting there for him with a gun. Dalton fights him again and knocks him into the water. Although Dalton tries to save Dell, the crocodile makes a meal of Dell first.
Dalton later learns of the shady business going on in town through Charlie. After he leaves the book store, a pair of Brandt’s goons try to force Dalton to go with them, but he breaks the fingers off the guy threatening him with a gun. Brandt learns that Dalton cannot be easily defeated, something that even his imprisoned criminal father Gerald becomes aware of.
Gerald contacts Knox (Conor McGregor), his toughest and nastiest goon, to head to Glass Key and deal with Dalton. This is after Knox walks out into the street in Italy nude after having an affair with a married woman, then assaulting a guy for his jacket and then setting a shop on fire. Knox arrives at Brandt’s home and lets him know that his father hired him, which neither Brandt nor his other criminal buddies are too happy about.
Dalton goes on a date with Ellie, who takes her ex’s boat out into the water. She tells Dalton she knows about his past, something that he has been trying to hide from everyone. Although he tries to walk away from Ellie, she gets him to stay and they kiss.
Later on, Dalton is found by Sheriff “Big Dick” (Joaquim de Almeida) and his dirty cops. The Sheriff orders and threatens Dalton to leave town, but he refuses. The cops then start to assault Dalton, with Dick getting ready to execute him until Ellie drives up and slaps him. She takes Dalton with her and informs him that Dick is her father. What’s more is that he is in cahoots with Brandt. Ellie then sincerely tells Dalton that he needs to leave town.
That night at the Road House, Brandt shows up and approaches Dalton. He starts to taunt him about his past in the UFC, as it turns out Dalton left because he killed his opponent in the ring even after the ref called the fight, and Dalton has been haunted about this ever since. After Brandt leaves, Knox arrives to start trouble. He beats on Billy and the other guys, leaving Dalton to step in. Knox proves to be a challenge for Dalton, but Knox ends up being surprised that Dalton manages to get back on his feet after a beatdown. Ellie arrives at the scene to provide medical attention.
As Dalton starts to leave town, he sees the book store on fire, done by Brandt’s goons Sam (Darren Barnet) and Vince (Beau Knapp). Dalton is told that Charlie and Stephen are at the hospital but are alive. He finds Vince, who threatens him with a gun until Dalton punches his throat and causes his trachea to collapse so he ultimately suffocates. While disposing of the body, Dalton sees Moe (Arturo Castro), a member of Dell’s gang who is the least rotten of them all. He tells Dalton of a meeting Brandt and his goons are going to have early the next day.
Dalton goes by the water and finds one of Dick’s corrupt deputies carrying a large case full of money onto a boat. He knocks the deputy out and plants Vince’s body there with him to frame the deputy for his death.
The Sheriff finds Dalton and informs him that Brandt kidnapped Ellie. Dalton makes it to Brandt’s yacht and sees Dick there with him, allowing him to figure out that Dick deliberately lured him onto the boat. However, Brandt admits that he really DID kidnap Ellie. Before the goons can gang up on him, Dalton blows up the boat he arrived (which belonged to Ellie’s ex) on to disorient everybody. The yacht starts to sink as a result, and Dalton beats the crap out of the goons before finding Ellie. She breaks through the window and gets out, along with Dalton.
Knox shows up in a skiff boat and tries to finish Dalton off while Brandt grabs Ellie and takes her onto a motorboat. Dalton makes it onto the motorboat while Knox falls into the water. Dalton fights Brandt and causes the motorboat to crash just outside the Road House, sending Brandt flying onto the roof. Meanwhile, Knox gets out of the water and steals a truck before crashing it into the Road House. When Brandt demands that Knox finally kill Dalton, Knox has enough of Brandt’s behavior and he snaps his neck. Dalton and Knox then go for round two, with Knox once again proving to be a beast, until Dalton manages to gain the upper hand and takes Knox out by stabbing him with wooden shards until he is down.
Dick shows up and offers to cover for Dalton as gratitude for saving Ellie. She and Dalton share one last look before he leaves. Frankie, Billy, Laura, and the others then start to try and clean up the destruction of the Road House while still staying open for business.
Just as Dalton gets ready to leave, he stops by the book store to see Charlie and Stephen there once more. He says goodbye to them and leaves them with the cash bag that he took from the deputy. Dalton then hops on a bus to his next destination.
During the credits, Knox is shown to have survived the fight. He beats up all the doctors and walks out of the hospital with nothing but a gown.
