Osamu Muramatsu (村松 修, Muramatsu Osamu, born 1949) is a Japanese astronomer and discoverer of asteroids and comets. He is credited by the Minor Planet Center with the discovery of 73 minor planets. He also co-discovered 147P/Kushida-Muramatsu, a periodic comet.
Muramatsu works at the planetarium in the Shibuya ward of Tokyo, Japan. The inner main-belt asteroid 5606 Muramatsu, discovered by astronomer and college Satoru Otomo, was named in his honor on 28 July 1999 (M.P.C. 35483).