Conrad Theodor "Coen" van Deventer (29 September 1857, in Dordrecht – 27 September 1915, in The Hague) was a Dutch lawyer, an author about the Dutch East Indies and a member of parliament of the Netherlands. He became known as the spokesman of the Dutch Ethical Policy Movement. He lived at Surinamestraat 20, The Hague (1903–1915), former residence of John Ricus Couperus, his son writer Louis Couperus and the rest of his family (1884–1902).