The Agout or Agoût is a 194.4-kilometre (120.8 mi) long river in south-western France. It is a left tributary of the Tarn. Its source is in the southern Massif Central, in the Haut-Languedoc Regional Nature Park. It flows generally west through the following department and towns:Hérault: La Salvetat-sur-Agout Tarn: Brassac, Castres, Lavaur, Saint-Sulpice