Final Fantasy XI, also known as Final Fantasy XI Online, is a massively multiplayer online role-playing game (MMORPG), developed and published by Square (later Square Enix) as the eleventh main installment of the Final Fantasy series.

The story is set in the fantasy world of Vana'diel, where player-created avatars can both compete and cooperate in a variety of objectives to develop an assortment of jobs, skills, and earn in-game item rewards. Players can undertake an array of quests and progress through the in-game hierarchy and through the major plot of the game. Since its debut in 2002, five expansion packs have been released along with six add-on scenarios. Each expansion pack and add-on brings a new major storyline to the Final Fantasy XI world, along with numerous areas, quests, events and item rewards.