The name Ansem is used to refer to several different characters in the Kingdom Hearts series:
- Ansem the Wise, the original ruler of Radiant Garden.
- Ansem, Seeker of Darkness, a Heartless who stole Ansem's the Wise identity.
- Terra-Xehanort, also known as Ansem, the original body of Ansem, Seeker of Darkness who stole the name before turning himself to darkness.
- Xemnas, whose name is an anagram of "Ansem" and an "X", Terra-Xehanort's Nobody and the leader of the original Organization XIII.
- Riku-Ansem, who took on the heart, appearance, and name of Ansem, Seeker of Darkness.