Trigun (Japanese: トライガン, Hepburn: Toraigan) is a Japanese manga series written and illustrated by Yasuhiro Nightow. It was first serialized in Tokuma Shoten's shōnen manga magazine Monthly Shōnen Captain from March 1995 to December 1996, until the magazine ceased its publication; its chapters were collected in three tankōbon volumes. The series continued its publication in Shōnen Gahosha's seinen manga magazine Young King OURs, under the title Trigun Maximum, from October 1997 to March 2007. Shōnen Gahosha republished the Trigun chapters in two volumes, and collected the Trigun Maximum chapters in 14 volumes.

Set on the fictional planet known as No Man's Land, the plot follows Vash the Stampede, a famous gunman who is constantly fighting bounty hunters seeking to obtain the immense bounty on his head. As the narrative progresses, Vash's past is explored. Trigun originated from Nightow's fascination with Western movies. Nightow wanted Vash to be different from cowboys in Western movies by avoiding killing enemies and instead exploring the characters involved in each story arc.

Trigun was adapted into a 26-episode anime television series by Madhouse; it aired on TV Tokyo from April to September 1998. An anime feature film, Trigun: Badlands Rumble, premiered in Japan in April 2010. A second anime television series adaptation produced by Orange, titled Trigun Stampede, premiered in January 2023. In North America, both manga series have been licensed by Dark Horse Comics. The anime series was first licensed by Geneon Entertainment and started broadcast in the United States, as part of Cartoon Network's Adult Swim programming block, in 2003; the series was later licensed by Funimation.

In 2009, Trigun Maximum won the Best Comic category at the 40th Seiun Awards. Critical response to the manga has been generally positive based on Vash and his friends' actions and relationships, as well as the handling of action scenes. However, critics disliked Vash's predicament in regards to his pacifism and the plot being hard to understand. The anime series was similarly positively received.

In the 32nd century, a man known as "Vash the Stampede" has earned a bounty of $$60 billion ("double dollar") on his head and the nickname "The Humanoid Typhoon" (人間台風) after accidentally destroying a city with his supernatural powers. However, whenever he is attacked, Vash displays a pacifist personality as noted by two Bernardelli Insurance Society employees, Meryl Stryfe and Milly Thompson, who follow him around in order to minimize the damages inevitably caused by his appearance. Most of the damage attributed to Vash is actually caused by bounty hunters in pursuit of the sixty billion double-dollar bounty on Vash's head for the destruction of the city of July. However, he cannot remember the incident due to retrograde amnesia, being able to recall only fragments of the destroyed city and memories of his childhood. Throughout his travels, Vash tries to save lives using non-lethal force. He is occasionally joined by a priest, Nicholas D. Wolfwood, who, like Vash, is a superb gunfighter with a mysterious past. As the series progresses, more about Vash's past and the history of human civilization on the planet is revealed.

Vash and his twin brother Knives were originally two children with a slow aging process found in a spaceship that escaped from the planet Earth after mankind had exhausted all its resources. Rem raised them, but Knives became nihilistic and had most of the people in the ship disposed of. As a result, Vash lives to find his twin and have revenge. Vash is targeted by Legato Bluesummers from the Gung-ho Guns assassins who are followers of Knives. Wolfwood himself is a Gung-Ho Gun but was hired to make sure Vash does not die and instead suffer. Vash and Knives both possess the Angel Arm, which Knives forced Vash to use in the series' beginning to destroy the town.

Vash eventually fights Knives, but is defeated. Wolfwood betrays Knives and saves Vash. In the aftermath, Wolfwood dies fighting one of the Gung-Hos; his friend, Livio, joins Vash's cause while grieving for his friend's death. As Knives approaches the city with the "Ark", a floating ship designed to leave humans without any resources and end life on the planet, Knives begins dueling with Vash. Throughout his past battles that required him to use the Angel's Arm, Vash has transformed into a regular human signified by his blond hair now turned black. Knives also starts losing the powers he stored with the Ark through Vash's actions. Vash then saves his brother from the vengeful ships from Earth. Following his defeat, Knives uses his last powers to help his weakened brother by creating a small fruit tree to feed him. After his brother's death, Vash continues his travels on the planet with Meryl and Milly.

After leaving college, Yasuhiro Nightow had gone to work selling apartments for the housing corporation Sekisui House, but struggled to keep up with his manga drawing hobby. Reassured by some successes, including a serialized manga based on the popular video game franchise Samurai Spirits for Family Computer Magazine, he quit his job to draw full-time. The series was conceptualized as a mix between Western and science fiction as Nightow found it not seen in Japan by the time he started writing Trigun. To contrast Vash from the typical heroes in action films, Nightow portrayed him as a pacifist since he did not want his lead character to be a murderer. Throughout the story, Vash avoids killing enemies by disarming them and avoids inflicting mortal wounds during combat. His cheerful personality was used to highlight this trait with his catchphrase being: "Hey, sorry. Love and peace?" Other elements of the manga were based on real life. Wolfwood's name was taken from the lead singer as his image for the priest. He is also modeled on Tortoise Matsumoto from the band Ulfuls. In order to create "warm" environments, Nightow drew several eating scenes.