Hitman is a series of stealth video games developed by Danish company IO Interactive and previously published by Eidos Interactive and Square Enix. IO Interactive remained a subsidiary of Square Enix until Square Enix began looking for buyers for the studio in 2017. IO Interactive made a management purchase in June 2017, regaining its independence and retaining the rights to Hitman. The series is available on Microsoft Windows and several video game consoles, including PlayStation 2, Xbox, GameCube, PlayStation 3, Xbox 360, PlayStation Vita, PlayStation 4 and Xbox One. The franchise also includes two novels and graphic novels: Hitman: Enemies In by William C. Dietz, followed by Hitman: Damnation by Raymond Benson, and the prequel agent for the comic book 47: Birth of a Hitman.

The 2007 movie version based on the plot of the game was negatively received, but was a financial success. Another movie, Hitman: Agent 47, released in 2015 also received negative reviews.

The game is based on Agent 47, a perfect clone contract killer who made it very popular with the rich and elite as he killed many of the most famous criminals around the world. The first scriptwriter was Morten Iversen, who wrote the script for Hitman: Codename 47 and Hitman 2: Silent Assassin. He also contributed to Hitman: Contracts and Hitman: Blood Money. The game offers a combination of orchestral and electronic music scores compiled by Jesper Kyd. The fifth episode of the series, Hitman: Absolution, is released on November 20, 2012. It releases a spin-off for PC, PlayStation 3 and Xbox 360 called Hitman: Sniper Challenge. For mobile phones and tablets, a spin-off game developed by Square Enix Montreal was released as a turn-based strategy game titled Hitman Go. Another game released for mobile, Hitman: Sniper, consists of the first person sniping game. The sixth game, Hitman, was released on a rolling basis, the first episode was released in March 2016 and the last in December 2016. The seventh game, Hitman 2, was released in November 2018.