Rolf Singer (1906 - 1994) was a German-born mycologist and one of the most important taxonomists of gilled mushrooms (agarics) in the 20th century. He wrote major books like "The Agaricales in Modern Taxonomy". He fled to various countries during the Nazi period, pursuing mycology in far-flung places like the Soviet Union, Argentina, and finally the United States, as mycologist at the Field Museum in Chicago.