Ogata Koan (?? ??, August 13, 1810 – July 25, 1863) was a Japanese physician and rangaku scholar in late Edo period Japan, noted for establishing an academy which later developed into Osaka University.
Many of his students subsequently played important roles in the Meiji Restoration and the westernization of Japan in the Meiji period.
His true name was Ogata Koreaki (?? ??) or Ogata Akira (?? ?); the name of Koan was his courtesy name.