First Blood (also known as Rambo: First Blood) is a 1982 American-Canadian action thriller film directed by Ted Kotcheff and co-written by and starring Sylvester Stallone as Vietnam War veteran John Rambo. It co-stars Richard Crenna as Rambo's mentor Sam Trautman and Brian Dennehy as Sheriff Will Teasle. It is the first installment in the Rambo franchise, followed by Rambo: First Blood Part II.

The film is based on the 1972 novel First Blood by David Morrell, which many directors and studios had unsuccessfully attempted to adapt in the 1970s. In the film, Rambo is a troubled and misunderstood Vietnam veteran who must rely on his combat and survival skills when a series of brutal events results in him having to survive a massive manhunt by police and government troops near the fictional small town of Hope, Washington.

First Blood was released in the United States on October 22, 1982. Initial reviews were mixed, but the film was a box office success, grossing $156 million and becoming the 13th highest grossing film at the domestic box office and the seventh highest grossing film worldwide. In 1985, it also became the first Hollywood blockbuster to be released in China, holding the record for the largest number of tickets sold for an American film until 2018. Since its release, it has been reappraised by critics, with many highlighting the roles of Stallone, Dennehy and Crenna, and recognizing it as an influential film in the action genre.

Its success spawned a franchise, consisting of four sequels (co-written by and starring Stallone), an animated television series, a comic books series, a novel series and several video games.