The Susa Valley (; ; ; ) is a valley in the Metropolitan City of Turin, Piedmont region of northern Italy, located between the Graian Alps in the north and the Cottian Alps in the south. It one of the longest valleys of the Italian Alps. It extends over in an east-west direction from the French border to the outskirts of Turin. The valley takes its name from the city of Susa which lies in the valley. The Dora Riparia river, a tributary of the Po, flows through the valley.