Hosoi Kōtaku (細井広沢, November 3, 1658 - February 4, 1736) was a Confucian scholar, calligrapher and seal carver in early Edo period Japan. He went by many pseudonyms during his career, including the pen-names of Jirō Tayū, Hirosawa, Tamagawa, Shiyosai, Shōrin-an, and Kisshō-dō. His calligraphy was highly praised in the pre-war period.