The Bienne (French pronunciation: [bjɛn]) is a 68.8 km (42.8 mi) long river in the Jura and Ain departments of eastern France. Its source is near Prémanon, Jura. It passes through the towns Morez and Saint-Claude. It discharges into the reservoir Lac de Coiselet, which is drained by the Ain, near Dortan.