Cavaglià is a comune (municipality) in the Province of Biella in the Italian region Piedmont, located about 50 kilometres (31 mi) northeast of Turin and about 20 kilometres (12 mi) south of Biella.

Cavaglià borders the following municipalities: Alice Castello, Carisio, Dorzano, Roppolo, Salussola, Santhià. Sights include a castle, the Baroque church of St. Michael Archangel, the neo-Renaissance church of Santa Maria di Babilone, and an archaeological site with menhirs from as early as the Iron Age.