Revised Romanization of Korean
As a Korean surname, Koh is a variant spelling of the surname most commonly spelled as Ko (based on its McCune–Reischauer transcription). This surname, also spelled Go in the Revised Romanization of Korean, is written with a character meaning "high" (; ), the same one used for the Chinese surname Gāo mentioned above. Among Koreans with this surname, the largest clan is the , named for its "bon-gwan" (clan hometown) of Jeju Island; they claim descent from , the first ruler of the kingdom of Tamna, which ruled Jeju until being absorbed by the Joseon dynasty.