Franz Wilhelm Neger (2 June 1868, Nuremberg – 6 May 1923, Dresden) was a German botanist, mycologist and dendrologist.
He studied chemistry and natural sciences at the University of Munich, where his influences included Adolf von Baeyer and Paul Groth. From 1893 he taught classes in natural sciences at the "German college" in Concepción, Chile, during which time, he conducted botanical and mycological research in the Andes and Patagonia as well as in areas in the vicinity of Concepción.
In 1897 he returned to Europe as a chemistry assistant at the industrial school in Munich. During the following year he taught classes in chemistry and sciences at a secondary school in Wunsiedel, and in 1899 became a custodian at the botanical museum in Munich. In 1902 he received his habilitation under the sponsorship of Karl Ritter von Goebel and Ludwig Radlkofer. Afterwards, he worked as a professor at the forest academies in Eisenach (from 1902) and Tharandt (1905–20), and in the meantime, took research trips to southern Spain (1907), Dalmatia (1909), Corsica (1911) and Sweden (several times). In 1920 he was named director of the botanical institute and gardens at the polytechnic institute in Dresden.