Nikolai Semenovich Kurnakov (Russian: ??????? ????????? ????????; 6 December 1860 – 19 March 1941) was a Russian chemist who was internationally recognized as the originator of physicochemical analysis and he was one of the principal founders of the platinum industry in the USSR.
A chemical reaction that he pioneered, known as the Kurnakov test, is still used to differentiate cis from trans isomers of divalent platinum and is his best-known contribution to coordination chemistry.