Aleu is located some 10 km south-east of Saint-Girons and 30 km west by south-west of Foix. It can be accessed by the D618 road coming from the west and following the northern border of the commune continuing to Biert in the east. The only access to the village by vehicle is by a small mountain road branching from the D618 at Castet d'Aleu. There is a small unsealed airstrip north-east of the village at approx 1000m altitude. The commune is very rugged with extensive forests. Apart from the village, there are numerous hamlets: Castet d'Aleu, Galas d'en Bas and Galas d'en Haut, La Trappe, La Bordasse, Biech, Pinsou, La Rouere and Fontale.[3]
The Ruisseau d'Aleu rises in the south of the commune and flows north through the centre of the commune and the village gathering many tributaries and continues to join the Arac which forms the entire northern border of the commune. The Ruisseau de Loule forms most of the eastern border and also flows into the Arac. In the west the Ruisseau de Regude forms most of the border and flows north-west to join the Arac north-west of the commune.[3]
