Allières is located in thePlantaurel mountains in theNatural Regional Park of Pyrénées ariégeoises some 22 km west by north-west ofFoix and some 70 km south ofToulouse. Access to the commune is by the minor D49 road which runs north from the D117 road through the commune and the village and continuing north across the mountains to join the D119 near Maury. There is also access by a minor road from the east. Apart from the village there is also the hamlet of Escougnale. The commune is heavily forested with a few farms.[3]
Numerous streams rise in the commune mostly flowing north to theRuisseau de Mourisse which forms the northern border of the commune and flows west to join theArize river near Maury. There is also theRuisseau de Peydalières rising in the west of the commune which flows west also to join the Arize.[3]