Chiyomatsu Ishikawa (石川 千代松 Ishikawa Chiyomatsu, January 30, 1861 - January 17, 1935) was a Japanese biologist, zoologist, evolutionary theorist, and ichthyologist at the Naples Zoological Station starting 1887. He was responsible for disseminating Darwin's ideas on evolution in Japan. After graduating from the University of Tokyo, he studied in Germany under eminent evolutionary theorist August Weismann. He was also the 5th principal of the Dokkyo Middle School in Tokyo.
