The Boondock Saints is a 1999 crime thriller film written and directed by Troy Duffy. The film stars Sean Patrick Flanery and Norman Reedus as Catholic Irish fraternal twins, Connor and Murphy MacManus, who become vigilantes after killing two members of the Russian Mafia in self-defense. After both experiencing an epiphany, the brothers, together with their friend David Della Rocco, set out to rid their home city of Boston, Massachusetts of crime and evil; all the while being pursued by FBI Special Agent Paul Smecker (Willem Dafoe).

Duffy indicates that the screenplay was inspired by personal experience, while living in Los Angeles. The film experienced a limited theatrical release of only five theaters for one week, and was met with poor critical reviews; but the film has grossed about $50 million in domestic video sales. It proved divisive among viewers, ultimately developing a large cult following. The ending credit sequence, which features the media asking the people of Boston, "Are the 'saints' good or evil?", was shot by Mark Brian Smith, co-director of Overnight, a documentary film about the making of The Boondock Saints, and Troy Duffy himself.

The film opens with Irish brothers Connor (Sean Patrick Flanery) and Murphy (Norman Reedus) MacManus attending Mass at a Catholic Church, where the priest mentions the fate of Kitty Genovese. Next, while celebrating St. Patrick's Day with friends, the two get into a bar brawl with three Russian mobsters who wanted to close the pub. The two brothers try to reason with the mobsters, but they responded with violence. The next morning, the bandaged bodies of two of the mobsters are found in an alley.