Sostegno is a comune (municipality) in the Province of Biella in the Italian region Piedmont , located about 80 kilometres (50 mi) northeast of Turin and about 20 kilometres (12 mi) northeast of Biella.

Sostegno borders the following municipalities: Crevacuore , Curino , Lozzolo , Roasio , Serravalle Sesia , Villa del Bosco . Economy is based on the production of apples and wine.