Kingdom Hearts: Chain of Memories is the second game in the Kingdom Hearts series. It is a direct sequel to Kingdom Hearts and exclusive to the Game Boy Advance. It was published by Square Enix and developed by Jupiter, and was released in 2004. Chronologically, it is the third game in the timeline after Kingdom Hearts Birth by Sleep and Kingdom Hearts, and takes place during Kingdom Hearts 358/2 Days.

Kingdom Hearts: Chain of Memories takes place directly after the ending of the first game, Kingdom Hearts. The game is set in Castle Oblivion, a mysterious castle kept by Lord Marluxia. Sora and his teammates are told that the castle causes visitors to lose their memories upon entering. The lobby and areas between floors are white with flower-themed decorations, but each floor can be transformed into a different world from the first Kingdom Hearts game using "world cards" created from Sora's memories. Like before, many of the worlds are based on Disney films while the rest were created by Square Enix.