Valle Mosso was a comune (municipality) in the Province of Biella in the Italian region Piedmont, located about northeast of Turin, northwest of Milan and northeast of Biella. Until December 31, 2018, it constituted an autonomous municipality, which bordered the municipalities of Bioglio, Campiglia Cervo, Mosso, Pettinengo, Strona, Trivero, Vallanzengo, Valle San Nicolao and Veglio.
As a comune it had the following frazioni: Campore, Crocemosso, Falcero, Frignocca, Gallo, Orcurto, Ormezzano, Piana, Picco, Prelle, Premarcia, Simone, Torello
From 1 January 2019 Valle Mosso was absorbed by the new-born municipality of Valdilana.