Wilhelm Körner (born April 20, 1839, Kassel, Hesse-Kassel [Germany]—died March 28, 1925, Milan, Italy) was a German organic chemist who in 1874 showed how to determine the relative positions of two substituents, such as methyl, on the benzene ring. For example, o-xylene forms two different mononitro derivatives; m-xylene forms three; and p-xylene forms only one. This method permitted further advances in the study and development of aromatic (benzene-derived) compounds.
A student and assistant of August Kekule at Ghent, Körner was appointed to the chair of chemistry at Bonn (1867) and to a chair of organic chemistry at Milan (1870). He prepared 126 aromatic compounds, including pyridine (1869). With Angelo Menozzi of Italy, he synthesized asparagine (1887).