Margarete Hedwig Zuelzer (7 February 1877 – 29 August 1943) was a German biologist and zoologist specializing in the study of protozoa.

[1] Studying science in particular was so unusual for a woman at the time that Zuelzer had to get special permission from each of her professors to attend their classes.

[6] Zuelzer wrote an appeal demonstrating her ancestors' support of German nationalism, but this made no difference.

In October 1939, Zuelzer immigrated to the Netherlands, where she procured a position at the Institute for Tropical Hygiene, which was led by Wilhelm Schüffner.

[1] Her sister Gertrud Zuelzer, a noted painter, was arrested in September 1942 and sent to Theresienstadt after a failed attempt to flee Germany to Switzerland.