The Orbieu is a 84.3-kilometre (52.4mi) long river in the Aude département, in south central France. Its source is at Fourtou, in the Corbières. It flows generally northeast. It is a right tributary of the Aude into which it flows between Raissac-d'Aude and Marcorignan, 10 kilometres (6mi) northwest of Narbonne.