San Marzano Oliveto is a comune in the Province of Asti in the Italian region of Piedmont (Piemonte in Italian), located about 37 miles (60 kms) southeast of Turin (Torino) and about 12.4 miles (20 kms) southeast of Asti and between Canelli and Nizza Monferrato. San Marzano Oliveto enjoys a panoramic position 300 metres above sea level. The town has a towered castle.