Baron Kitasato Shibasaburō (January 29, 1853 – June 13, 1931) is a Japanese physician and bacteriologist.

He is remembered as the co-discoverer of the infectious agent of bubonic plague in Hong Kong in 1894, almost simultaneously with Alexandre Yersin.

Kitasato is nominated for the first annual Nobel Prize in Physiology or Medicine in 1901.

Kitasato and Emil von Behring, working together in Berlin in 1890, had announced the discovery of diphtheria antitoxin serum.

Von Behring is awarded the 1901 Nobel Prize because of this work, but Kitasato is not.