Samuel Friedrich Nathaniel Ritter von Stein (November 3, 1818 - January 9, 1885) was a German entomologist chiefly interested in Diptera.
Born in Niemegk near Potsdam, Brandenburg, in 1850, Stein became a Professor at the Forest and Agriculture Institute in Tharandt in Sachsen (Saxony), 20 km south-west of Dresden. This was one of the leading forestry schools in Germany. Formal education in forestry began about 1840 when private forestry schools were established. These were the outgrowth of the old master schools. The forestry college at Tharandt developed from Cotta Master School. Though not of the same order Tharandt had close connections with the French National School of Forestry which was established in Nancy, France in 1825. The work at Tharandt, under Stein's supervision was of a very high order, thoroughly professional and of very high technical standards. In 1855 he became professor at the University of Prague and served as a rector of the university in the year 1875/6. He was ennobled on April 27, 1878 in Vienna by Franz Josef I.