The terms Unknown (謎の男, Nazo no Otoko, "Enigmatic Man") or ??? can refer to a several different characters in the Kingdom Hearts series:
- Xemnas in Kingdom Hearts Final Mix.
- Marluxia in Kingdom Hearts: Chain of Memories.
- Riku in Kingdom Hearts II or Kingdom Hearts 358/2 Days.
- Xion in Kingdom Hearts 358/2 Days.
- Young Xehanort in Kingdom Hearts Birth by Sleep.
- Data-Roxas in Kingdom Hearts coded.
- Lingering Will in Kingdom Hearts II Final Mix.
- The Master of Masters and Luxu in Kingdom Hearts χ.
- Ephemer and The Master of Masters in Kingdom Hearts III.
- Tommy Oliver in How The Chipmunks and Chipettes Joined the Disney Family (non-canon).
The Unknown is a recurring title in Kingdom Hearts Fanon. It can refer to...
- The Unknown - The optional superboss of Avastar: Kingdom Hearts.
- The Unknown - A character in Kingdom Hearts Legacy.
- Unknown - A character in Kingdom Hearts: Shattered.