Asciano is a town in the province of Siena in the Italian region of Tuscany. It is located in the centre of the Crete Senesi between the Ombrone river and the Copra torrent, about 30 km southeast of the city of Siena.
Asciano is of Etruscan origin, later it was Roman and then Lombard. In 1898 an Etruscan necropolis and the remains of Roman baths, with mosaics on the floor, were found during excavations. During the medieval period its location made it a disputed place between Siena and Florence: the battle of Montaperti took place in its vicinity on 4 September 1260. The city was bought by the Sienese in 1285 and surrounded by walls in 1351. It has 14 centuries-old churches with paintings of that period.