Rosazza is a comune (municipality) in the Province of Biella in the Italian region Piedmont, located about northeast of Turin and about northwest of Biella. As of 31 December 2004, it had a population of 89 and an area of .
Rosazza borders the following municipalities: Andorno Micca, Campiglia Cervo, Piedicavallo, Sagliano Micca. It is one of I Borghi più belli d'Italia ("The most beautiful villages of Italy").