Kingdom Hearts II is a 2005 action role-playing game developed and published by Square Enix in collaboration with Buena Vista Games for the PlayStation 2 video game console. The game is a sequel to Kingdom Hearts, and like the original game, combines characters and settings from Disney films with those of Square Enix's Final Fantasy series. An expanded re-release of the game featuring new and additional content, Kingdom Hearts II Final Mix, was released exclusively in Japan in March 2007. The Final Mix version of the game was later remastered in high definition and released globally as a part of the Kingdom Hearts HD 2.5 Remix collection for the PlayStation 3, PlayStation 4, Xbox One, Windows, and Nintendo Switch.

Kingdom Hearts II is the third game in the Kingdom Hearts series. It picks up one year after the events of Kingdom Hearts: Chain of Memories. Sora, the protagonist of the first two games, returns to search for his lost friends while battling the sinister Organization XIII, a group of antagonists previously introduced in Chain of Memories. Like the previous games, Kingdom Hearts II features a large cast of characters from Disney and Square Enix properties.

Concepts for Kingdom Hearts II began during the end of development of Kingdom Hearts Final Mix, with the game entering full development in 2003 and being announced at Tokyo Game Show 2003. Most of the first game's development team returned, including director Tetsuya Nomura, with the game being developed concurrently with Chain of Memories. In developing Kingdom Hearts II, the development team sought to address user feedback from the first game, give the player more freedom and options in combat and present a deeper and more mature plot.

The game received critical acclaim, as it earned several awards upon release, receiving critical praise for its story, gameplay, characters, graphical improvements, and has since been cited as one of the greatest video games of all time.In both Japan and North America, it shipped more than one million copies within weeks of its release, with over four million worldwide by April 2007.