Berthold Carl Gustav Giemsa (German: [ˈɡiːmzaː]; November 20, 1867 – June 10, 1948) was a German chemist and bacteriologist who was a native of Medar-Blechhammer (now part of the city Kędzierzyn-Koźle). He is best known for creating a dye solution commonly known as "Giemsa stain" which is used in staining for use in the histopathological diagnosis of malaria and parasites such as Plasmodium, Trypanosoma, and Chlamydia.