San Giacomo Vercellese is a comune (municipality) in the Province of Vercelli in the Italian region Piedmont, located about 70 kilometers northeast of Turin and about 20 km northwest of Vercelli. As of 31 December 2004, it had a population of 352 and an area of 9.6 km². San Giacomo Vercellese borders the following municipalities: Arborio, Balocco, Buronzo, Rovasenda, and Villarboit.