Menziesia sebastodis (Capsalidae: Monogenea) is found and described from the gill filaments and the gill rakers of the black rockfish, Sebastes inermis, caught at Dolsan Island, off the south coast of Yeosu, Jeollanam-do, Korea. The genus Menziesia is distinguished from other related genera Benedenia, Megalobenedenia and Trochopus, by septate haptors and the morphology of copulatory organs. M. sebastodis can be differentiated from other Menziesia species by the longer and slenderer posterior anchor, and the location of accessory gland reservoir. This is the first record of the genus Menziesia in Korea.