Rolf Singer (June 23, 1906 – January 18, 1994) was a German mycologist and taxonomist of gilled mushrooms (agarics).

He fled to various countries during the Nazi period, pursuing mycology in the Soviet Union, Argentina, and finally the United States, as mycologist at the Field Museum in Chicago.

Persecution by the Spanish authorities on behalf of the German government forced Singer to leave Spain for France in 1934.

After a fellowship at the Museum d'Histoire Naturelle in Paris, Singer again moved, this time to Leningrad, where he was senior scientific expert at the Botanical Garden of the Academy of Sciences of the USSR.

During this time, Singer also received a Guggenheim Fellowship for studies in Florida, and taught at the Mountain Lake Biological Station of the University of Virginia.