Overwatch was a 2016 team-based multiplayer first-person shooter game by Blizzard Entertainment. The game was first released for PlayStation 4, Windows, and Xbox One in May 2016 and Nintendo Switch in October 2019. Cross-platform play was supported across all platforms.

Described as a "hero shooter", Overwatch assigned players into two teams of six, with each player selecting from a large roster of characters, known as "heroes", with unique abilities. Teams worked to complete map-specific objectives within a limited period of time. Blizzard added new characters, maps, and game modes post-release, all free of charge, with the only additional cost to players being optional loot boxes to purchase cosmetic items.

Overwatch is Blizzard's fourth major franchise and came about following the 2014 cancellation of a massively multiplayer online role-playing game, Titan. A portion of the Titan team were inspired by the success of team-based first-person shooters like Team Fortress 2 and the popularity of multiplayer online battle arena games, creating a hero-based shooter which emphasized teamwork. Some elements of Overwatch borrow concepts from the canceled Titan project.

Overwatch was unveiled at the 2014 BlizzCon event and was in a closed beta from late 2015 through early 2016. An open beta before release drew in nearly 10 million players. Overwatch received universal acclaim from critics, who praised the game for its accessibility, the diverse appeal of its hero characters, its cartoonish art style, and enjoyable gameplay. Blizzard reported over US$1 billion in revenue during the first year of its release and had more than 50 million players after three years. Overwatch is considered to be among the greatest video games ever made, receiving numerous game of the year awards and other accolades. The game is a popular esport, with Blizzard funding and producing the global Overwatch League.

A sequel, Overwatch 2, was announced in 2019 and entered beta in 2022. The player versus player portion of the game is free to play, with all cosmetic items from Overwatch carried over while introducing new heroes, maps, and gamemodes. A player versus environment (PvE) co-operative multiplayer mode will be released at a later time. On October 3, 2022, the Overwatch servers were shut down in preparation for the release of Overwatch 2 the next day.