Sahachiro Hata (? ???, Hata Sahachiro, March 23, 1873 – November 22, 1938) was a prominent Japanese bacteriologist who assisted in developing the Arsphenamine drug in 1909 in the laboratory of Paul Ehrlich.
He was nominated for the Nobel Prize in Chemistry in 1911 and for the Nobel Prize in Physiology or Medicine in 1912 and 1913.