Duke Nukem 3D is a first-person shooter video game developed by 3D Realms and published by GT Interactive Software. It is a sequel to the platform games Duke Nukem and Duke Nukem II, published by 3D Realms.

Duke Nukem 3D features the adventures of the titular macho Duke Nukem, voiced by Jon St. John, who fights against an alien invasion on Earth. Along with Wolfenstein 3D and Doom, Duke Nukem 3D is considered to be responsible for popularizing first-person shooters, and was released to major acclaim. Reviewers praised the interactivity of the environments, gameplay, level design, and unique risqué humor, a mix of pop-culture satire and lampooning of over-the-top Hollywood action heroes. The game's violent nature, erotic elements, and portrayal of women incited controversy.

The shareware version of the game was originally released on January 29, 1996, while the full version was released on April 19, 1996 as version 1.3d. The Plutonium PAK, an expansion pack which updated the game to version 1.4 and added a fourth eleven-level episode, was released in November 1996. The Atomic Edition, a standalone version of the game that included the content from the Plutonium PAK and updated the game to version 1.5, was later released; the original version of Duke Nukem 3D has since been discontinued. An official fifth episode was released on October 11, 2016 with 20th Anniversary World Tour published by Gearbox Software. After fifteen years in development hell, a direct sequel was released in 2011 called Duke Nukem Forever.