Hard Boiled (Chinese: 辣手神探; lit. 'Hard Boiled Detective') is a 1992 Hong Kong action film directed by John Woo from a screenplay by Gordon Chan and Barry Wong, based on a story by Woo. The film stars Chow Yun-fat as Inspector "Tequila" Yuen, alongside Tony Leung Chiu-wai and Teresa Mo. It follows a hard-boiled police inspector whose pursuit of a violent Triad syndicate draws him into a dangerous operation involving an undercover officer working deep within the criminal organization.

The film was Woo's final Hong Kong film before his transition to Hollywood. Conceived in response to criticism that his earlier works romanticized criminals, Woo aimed to create a police-centered action film inspired by the Dirty Harry series. Production was marked by extensive improvisation and ongoing script revisions, particularly following the death of co-writer Barry Wong. Several characters and narrative elements were introduced or reworked during filming, while earlier story concepts—including a subplot involving a child-targeting criminal—were abandoned.

Hard Boiled was released theatrically in Hong Kong in 1992 to strong audience response. Although it did not match the domestic box-office success of Woo's A Better Tomorrow (1986), it outperformed The Killer (1989) in the local market. Internationally, the film received widespread critical acclaim, with particular praise for its elaborate gunfight choreography, long takes, and kinetic visual style.

Over time, Hard Boiled has come to be regarded as a landmark of Hong Kong action cinema and one of the defining works of the heroic bloodshed genre. Its action sequences—especially the extended hospital shootout—are frequently cited by critics and filmmakers as among the most accomplished in the history of the genre. The film has since achieved cult status and has been recognized as a major influence on action cinema worldwide. In 2007, a sequel in the form of a video game, Stranglehold, was released, with Chow Yun-fat reprising his role and Woo serving as creative director.

In a Hong Kong teahouse, Royal Hong Kong Police inspectors "Tequila" Yuen and Benny Mak surveil a group of gun smugglers while they are making a deal. When a rival gang ambushes the deal, a fierce shootout breaks out; the gangsters are defeated, but several police officers and civilians are wounded and Benny is killed. As revenge, Tequila executes the gangster who killed Benny rather than arrest him. He is reprimanded by Chief Superintendent Pang, who needed the executed gangster as a key witness. After a police funeral, Pang burns the personnel file of another smuggler Tequila killed, revealing him to be an undercover cop.

Meanwhile, Alan, an assassin working for Triad boss "Uncle" Hoi, murders one of Hoi's subordinates who had double-crossed them for a rival syndicate led by upstart Johnny Wong. Wong, who is looking to usurp the old Triad bosses through his control of the illicit arms trade, is impressed by Alan's skill and attempts to recruit him. Alan reluctantly accepts the offer, and Wong brings Alan to a raid on Hoi's warehouse as an initiation, where many of Hoi's men are killed. Surrounded, Hoi lets Alan kill him to spare his surrendering men, but Alan kills them all anyway to please Wong. Tequila, who has been watching from cover, ambushes and defeats Wong's men, but is caught by Alan, who spares him. Tequila confronts Pang, demanding to know if Alan is an undercover cop. Pang refuses to say, but reveals the teahouse friendly fire killing to Tequila and warns him to stay away from the case.

Tequila tracks Alan to his sailboat and deduces he is undercover, but they are ambushed by the remnants of Hoi's gang. The pair fight off the attackers and Tequila flees just before Wong arrives, allowing Alan to keep his cover. Wong realizes that one of his lieutenants, Foxy, is a police informant. Wong's henchman, Mad Dog, beats Foxy before Alan is ordered to execute him with a shot to the chest, but before that he manages to place cigar lighter in Foxy's chest pocket that saves his life. Foxy finds Tequila at a jazz bar and informs him that Wong's armory is hidden in a vault beneath the Maple hospital. As Tequila takes Foxy to the hospital, Wong discovers that Foxy is alive and sends Alan to kill him, while also discreetly sending Mad Dog to monitor Alan. At the hospital, Alan confronts Tequila, demanding to know the whereabouts of the vault; while the two are distracted, Mad Dog kills Foxy.

Alan and Tequila discover Wong's vault, where they briefly skirmish with Mad Dog. As Pang, officer Teresa Chang, and other inspectors evacuate the hospital, Wong and his men attempt to gain leverage by taking the staff and patients hostage while indiscriminately shooting fleeing patients and responding police officers, irritating Mad Dog with his callousness. Alan and Tequila team up to rescue the hostages and battle Wong's men; meanwhile, Pang evacuates the lobby and takes command at the police perimeter, while Chang and the Special Duties Unit rescue trapped babies from the maternity wing. As they fight their way through the hospital, Alan accidentally shoots a plainclothes officer and is overcome with guilt; Tequila consoles him by sharing his similar experience from the teahouse and encourages him to fight on.