Halo: Combat Evolved Anniversary is a 2011 first-person shooter video game developed by 343 Industries, Saber Interactive, and Certain Affinity. It is a remake of Halo: Combat Evolved (2001), developed by Bungie. Publisher Microsoft announced Anniversary alongside Halo 4 at the 2011 Electronic Entertainment Expo. It was released in November 2011, the 10th anniversary of the original Halo, for the Xbox 360 console, and re-released as part of Halo: The Master Chief Collection for the Xbox One in November 2014. A Windows version was released in March 2020.

Halo: Combat Evolved is a 2001 first-person shooter video game developed by Bungie and published by Microsoft Game Studios for the Xbox. It was released as a launch game for Microsoft's Xbox video game console on November 15, 2001. The game was ported to Microsoft Windows and Mac OS X in 2003. It was later released as a downloadable Xbox Original for the Xbox 360. Halo is set in the twenty-sixth century, with the player assuming the role of the Master Chief, a cybernetically enhanced supersoldier. The Chief is accompanied by Cortana, an artificial intelligence. Players battle aliens as they attempt to uncover the secrets of the eponymous Halo, a ring-shaped artificial world.