Sillavengo is a comune (municipality) in the Province of Novara in the Italian region of Piedmont, located about 80 kilometres (50 mi) northeast of Turin and about 15 kilometres (9 mi) northwest of Novara.

Sillavengo borders the following municipalities: Arborio, Briona, Carpignano Sesia, Castellazzo Novarese, Ghislarengo, Landiona, and Mandello Vitta.