Counter-Strike: Global Offensive (CS:GO) is a 2012 multiplayer tactical first-person shooter developed by Valve and Hidden Path Entertainment. It is the fourth game in the Counter-Strike series. Developed for over two years, Global Offensive was released for OS X, PlayStation 3, Windows, and Xbox 360 in August 2012, and for Linux in 2014.

The game pits two teams, Terrorists and Counter-Terrorists, against each other in different objective-based game modes. The most common game modes involve the Terrorists planting a bomb while Counter-Terrorists attempt to stop them, or Counter-Terrorists attempting to rescue hostages that the Terrorists have captured. There are nine official game modes, all of which have distinct characteristics specific to that mode. The game also has matchmaking support that allows players to play on dedicated Valve servers, in addition to community-hosted servers with custom maps and game modes. A battle-royale game-mode, "Danger Zone", was introduced in late 2018.

Global Offensive received positive reviews from critics on release, who praised the game for its gameplay and faithfulness to the Counter-Strike series, though it was criticized for some early features and the differences between the console and PC versions. Since its release, it has drawn in an estimated 11 million players per month and remains one of the most played games on Valve's Steam platform. In December 2018, Valve transitioned the game to a free-to-play model, focusing on revenue from cosmetic items.

The game has an active esports scene, continuing the history of international competitive play from previous games in the series. Teams compete in professional leagues and tournaments, with the game often cited as being among the best in esports.

Counter-Strike 2, a major update bringing the game to the Source 2 engine, was announced on March 22, 2023, and was released on September 27, 2023. Official matchmaking for Global Offensive was shut down that day, though players were still able to connect to community servers. A legacy version of Global Offensive was later released for outdated devices and platforms unable to run Counter-Strike 2, though matchmaking was still disabled. Additionally, the game remains playable on Xbox 360.