Sinio is a comune (municipality) in the Province of Cuneo in the Italian region Piedmont, located about southeast of Turin and about northeast of Cuneo. As of 1 January 2017, it had a population of 529 and an area of .
Sinio borders the following municipalities: Albaretto della Torre, Cerreto Langhe, Montelupo Albese, Roddino, Rodello, and Serralunga d'Alba.