Ourthe is a river in the Ardennes in Belgium. It is a tributary to the river Meuse. The Ourthe is formed at the confluence of the Ourthe Occidentale (Western Ourthe) and the Ourthe Orientale (Eastern Ourthe), west of Houffalize.

The source of the Ourthe Occidentale is near Libramont-Chevigny, in the Belgian province Luxembourg. The source of the Ourthe Orientale is near Gouvy, also in the Belgian province Luxembourg, close to the border with Luxembourg.

After the confluence of the two Ourthes, the Ourthe flows roughly in north-west direction. It flows into the river Meuse in the city Liège. The most important tributaries of the river Ourthe are the Amblève and the Vesdre. Towns along the Ourthe are Houffalize (Ourthe Orientale), La Roche-en-Ardenne, Hotton, Durbuy, Hamoir and Esneux.

See also

• Département de l'Ourte