Asada Gōryū (麻田 剛立, March 10 1734 – June 25 1799) was a Japanese astronomer who helped to introduce modern astronomical instruments and methods into Japan. Asada spent much of his career in the flourishing commercial city of Osaka, where he practiced medicine for a living. Because of the Japanese government's policy of seclusion, Western scientific theory was generally available only through obsolete Chinese works edited by Jesuit missionaries in China. Yet Asada managed to construct sophisticated mathematical models of celestial movements and is sometimes credited with the independent discovery of Kepler's third law.
The crater Asada on the Moon is named after him.