The term Berserk or Berserker can refer to several different things in the Kingdom Hearts series:
- The Nobodies that are led by Saïx in Kingdom Hearts II.
- The Reaction Command that appears while fighting Saïx or his Nobodies in Kingdom Hearts II.
- The Claymore that is usable by Saïx in Kingdom Hearts 358/2 Days.
- The Limit Break usable by Saïx in Kingdom Hearts 358/2 Days.
- The ability from Kingdom Hearts, Kingdom Hearts Chain of Memories, and Kingdom Hearts Birth by Sleep, usable by Sora, Donald Duck, Goofy, Tarzan, Beast, and Zack.
- The ability from Kingdom Hearts II, usable by Sora.