Arette is a very large commune and has a land area of . It is also mountainous (the La Pierre Saint-Martin ski resort is within its borders, for example) and its highest peak is the 2,315 m Soum Couy, which is situated not far from the 2,504 m Pic d'Anie, the highest peak in the western Pyrenees. From Pic d'Anie the mountain range extends downwards for approximately 20 km, forming both sides of the Aspe Valley to the north-west. The Vert d'Arette (a tributary of the Vert) flows through this valley. The ancient village (also named Arette) from which the commune extends is located at an altitude of 316 m in the valley of Barétous, which lies between the aforementioned Aspe valley, to its east, and the Basque province of Soule, to its west.