Hermann Schlegel (10 June 1804 – 17 January 1884) was a German ornithologist and herpetologist.
Schlegel was born at Altenburg, the son of a brassfounder. His father collected butterflies, which stimulated Schlegel's interest in natural history. The discovery, by chance, of a buzzard's nest led him to the study of birds, and a meeting with Christian Ludwig Brehm.
Schlegel started to work for his father, but soon tired of it. He travelled to Vienna in 1824, where, at the university, he attended the lectures of Leopold Fitzinger and Johann Jacob Heckel. A letter of introduction from Brehm to Joseph Natterer gained him a position at the Naturhistorisches Museum.
One year after his arrival, the director of this natural history museum, Carl Franz Anton Ritter von Schreibers, recommended him to Coenraad Jacob Temminck, director of the natural history museum of Leiden, who was seeking an assistant. At first Schlegel worked mainly on the reptile collection and wrote Essai sur la Physionomie des Serpens (1837), but soon his field of activity extended to other zoological groups. It had been intended that Schlegel be sent to Java to join the Natural History Commission, but the untimely death of Temminck's intended successor, Heinrich Boie, prevented the realization of this project.
It was at this time that Schlegel met Philipp Franz von Siebold. They became firm friends and collaborated on Fauna Japonica (1845-1850).