Richard Emil Benjamin Sadebeck (20 May 1839 in Breslau – 11 February 1905 in Meran) was a German pteridologist and mycologist. He was an older brother of mineralogist Alexander Sadebeck (1843–1879).
He studied natural sciences at the University of Breslau as a pupil of Heinrich Göppert. From 1865 to 1876 he worked as a schoolteacher in Berlin, and afterwards relocated to Hamburg, where he taught classes at the Johanneum. From 1883 to 1901 he was director of the Hamburg Botanical Museum.
In 1893 he described the fungal genus Magnusiella (syn. Taphrina).