The Versoix is a river in France and in Switzerland. It is a 21.8 km tributary of Lake Geneva. Its catchment area is 90.7 km2, of which 72.6 km2 in France. The river begins in the Jura Mountains in Ain, France as Rivière la Divonne. It flows eastward through Divonne-les-Bains and Lac de Divonne approaching the Canton of Vaud. From there it turns southward toward form 10.5 km of the France–Switzerland border, entering the Canton of Geneva and continuing eastward toward Versoix where it enters the lake.