Gotthelf Fischer von Waldheim (Russian: Григо́рий Ива́нович Фи́шер фон Ва́льдгейм, romanized: Grigórij Ivánovič Fíšer fon Vál'dgejm; 13 October 1771 – 18 October 1853) was a Saxon anatomist, entomologist and paleontologist.

Fischer was born as Gotthilf Fischer in Waldheim, Saxony, the son of a linen weaver. He studied medicine at Leipzig. He travelled to Vienna and Paris with his friend Alexander von Humboldt and studied under Georges Cuvier. He took up a professorship at Mainz, and then in 1804 became Professor of Natural History and Director of the Demidov Natural History Museum at the Moscow University. In August 1805 he founded the Société Impériale des Naturalistes de Moscou. Fischer was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 1812 and a member of the American Philosophical Society in 1818.

Fischer was mainly engaged in the classification of invertebrates, the result of which was his Entomographia Imperii Rossici (1820–1851). He also spent time studying fossils from the area around Moscow.

Due to his work studying the insects of Russia, the Russian government granted him nobility as well as the "von Waldheim" ending to his name.