High Counselor was the title used to designate the leader of the Ancient Council in Atlantis. The last High Counselor of Atlantis was Moros. (SGA: "Before I Sleep")
The leader of the Asurans was also styled High Counselor. At the time the Atlantis Expedition made contact with them, Oberoth was High Councilor of Asuras. (SG1: "Progeny", "First Strike")
High Counselor is also the title used to designate the leader of the Untouched in the Land of Light. Tuplo holds the title. (SG1: "The Broca Divide")