Ogata Koan

Statue of Koan Ogata at his birthlace in Okayama

Koan Ogata (緒方洪庵; August 13, 1810 - July 25, 1863) was a Japanese physician who lived in the Edo period.

He is well-known for importing Western medical knowledge into Japan during Japan's isolationist era (see Rangaku), and for establishing the Tekijuku (適塾) school that later developed into Osaka University in 1938. Famous alumni of the Tekijuku include Fukuzawa Yukichi, Otori Keisuke or Takeda Ayasaburō.

He was the author of "Byogakutsũron" (病学通論), which was the first book on pathology to be published in Japan.