World of Warcraft (WoW) is a massively multiplayer online role-playing game (MMORPG) released in 2004 by Blizzard Entertainment. Set in the Warcraft fantasy universe, World of Warcraft takes place within the world of Azeroth, approximately four years after the events of the previous game in the series, Warcraft III: The Frozen Throne. The game was announced in 2001, and was released for the 10th anniversary of the Warcraft franchise on November 23, 2004. Since launch, World of Warcraft has had nine major expansion packs: The Burning Crusade (2007), Wrath of the Lich King (2008), Cataclysm (2010), Mists of Pandaria (2012), Warlords of Draenor (2014), Legion (2016), Battle for Azeroth (2018), Shadowlands (2020), and Dragonflight (2022).

Similar to other MMORPGs, the game allows players to create a character avatar and explore an open game world in third- or first-person view, exploring the landscape, fighting various monsters, completing quests, and interacting with non-player characters (NPCs) or other players. The game encourages players to work together to complete quests, enter dungeons and engage in player versus player (PvP) combat, however, the game can also be played solo without interacting with others. The game primarily focuses on character progression, in which players earn experience points to level up their character to make them more powerful and buy and sell items using in-game currency to acquire better equipment, among other game systems.

World of Warcraft was a major critical and commercial success upon its original release in 2004 and quickly became the most popular MMORPG of all time, reaching a peak of 12 million subscribers in 2010. The game had over one hundred million registered accounts by 2014 and by 2017, had grossed over $9.23 billion in revenue, making it one of the highest-grossing video game franchises of all time. The game has been cited by gaming journalists as the greatest MMORPG of all time and one of the greatest video games of all time and has also been noted for its long lifespan, continuing to receive developer support and expansion packs over 15 years since its initial release. In 2019, a vanilla version of the game titled World of Warcraft Classic was launched, allowing players to experience the base game before any of its expansions launched, with versions of Classic for the second and third expansions being released subsequently, with minor changes. In 2022, Blizzard and NetEase cancelled an unannounced World of Warcraft mobile spin-off game.