Isao Sasaki(ささき いさお（佐々木功）Sasaki Isao, May 16, 1942–) is a Japanese seiyū, actor, and vocalist. He has had voice roles in anime such as Legend of the Galactic Heroes, Space Battleship Yamato, and Gatchaman. He has also performed the opening themes for anime such as Yamato, Star of the Giants, Getter Robo, Casshan, Grendizer, Gaiking and tokusatsu series such as Himitsu Sentai Goranger, J.A.K.Q. Dengekitai, Choujinki Metalder, and most recently Tokusou Sentai Dekaranger. He has also had an acting role in the tokusatsu film Kamen Rider ZO and in the series Kyojuu Tokusou Juspion. He is the dub voice of Clark Kent and Superman in the film series, until he was replaced by Hiroki Touchi for Superman Returns.