The Yvette is a small river in southern Île-de-France (France), left tributary of the Orge, which is a tributary of the Seine. It is 39.3 km (24.4 mi) long. Its source is in Les Essarts-le-Roi, north of Rambouillet, in the Yvelines department. Various communes of the Essonne department are named after it: Bures-sur-Yvette, Gif-sur-Yvette and Villebon-sur-Yvette.