The name of the town takes origin from Saint Agatha of Sicily; it s situated in a flat area before the mountains. Santhià covers an overall area of about 53 km² and it is placed in the plain of Vercelli, in the neighbourhood of moreniche (morainal) hills; it is a crossroads which connects its provincial capital to Biella, Ivrea and Milan. The town is surrounded by cornfield (North-West) and by rice (South-East).

The toponym takes origin from Saint Agatha of Sicily, the martyr of Catania and procuress of the village; also the church is dedicated to Saint Agatha, as the Lombard’s Queen Theodelinda decided. Santhià is an important road junction and a fervent cultural centre, since around one hundred groups and associations are involved in activities in the area.