Santhià Italian: [san'tja] (Piedmontese: Santhià or Sant'Àgata) is a comune (municipality) in the province of Vercelli in the Italian region Piedmont, located about 50 kilometres (31 mi) northeast of Turin and about 20 kilometres (12 mi) northwest of Vercelli.Santhià is well known for its historic carnival named the Carnevale Storico di Santhià since the 14th century. The medieval castle of Vettignè is located within the communal territory.