San Damiano d'Asti (Piedmontese: San Damian) is a comune (municipality) in the Province of Asti in the Italian region Piedmont, located about southeast of Turin and about southwest of Asti.
The area of the municipality was once occupied in the Middle Ages by the commune of Axtizio and its suburbs of Gorzano, Lavezzole and Marcelengo. In 1275, after losing the war against Asti, Astixio was destroyed. The Astigiani built in its place a new town, called San Damiano d'Asti.
San Damiano is twinned with: