Zenshu (also known as Zenju, 723 - May 25, 797) was a Buddhist priest who lived from the Nara period to the beginning of the Heian period. His secular surname was Ato. He was born in Yamato Province. It is thought that he founded Akishino-dera Temple. He was one of the Hosso Rokuso (Six High Priests of the Hosso Sect).
Zenshu studied under Genbo, and later he acquired expertise in Inmyo (Buddhist logic) of the Hosso (Dharma Characteristics) school. In 793, he was assigned as the chief priest of the kuyo (a memorial service for the dead) at Monju-do Hall on Mt. Hiei, and the following year, in 794, he conducted the completion ceremony of Enryaku-ji Temple's Konpon-chudo Hall as the doshi (head priest). In 796, as the doshi (head priest), he conducted the memorial ceremony with the Hokekyo (Lotus Sutra) for the late MONONOBE no Komaro held at the command of Emperor Kammu. In 797, he was assigned as the sojo (the official Buddhist priest in the highest position) due to his achievement in praying for the cure of the disease that had afflicted Imperial Prince Ate (Emperor Heizei). Shortly after that, he died at the age of 75. He was one of foremost writers in the history of Nara Buddhism, and he left more than 20 literary works such as "Yuishikigi tozomyoki" (an annotation of Buddhist scriptures) and "Yuishiki bunryo ketsu."