Susa (Latin: Segusio, French: Suse, Arpitan: Suisa) is a town and comune in the Metropolitan City of Turin, Piedmont, Italy.

In the middle of Susa Valley, it is situated on at the confluence of the Cenischia with the Dora Riparia, a tributary of the Po River, at the foot of the Cottian Alps, 51 km (32 mi) west of Turin.

[clarification needed] Remains of the Roman city have been found in the excavations of the central square, the Piazza Savoia.

In the Middle and Modern ages, Susa remained important as a hub of roads connecting southern France to Italy.

The city's role as a communications hub has been confirmed recently by a nationwide dispute over the construction of the proposed Turin-Lyon high-speed rail link (TAV) to France.