Chiuro (Lombard: Ciür) is a comune (municipality) in the Province of Sondrio in the Italian region of Lombardy, located about 100 kilometres (62 mi) northeast of Milan and about 9 kilometres (6 mi) east of Sondrio, on the border with Switzerland. As of 31 December 2004, it had a population of 2,499 and an area of 51.8 square kilometres (20.0 sq mi).
The municipality of Chiuro contains the frazioni (subdivisions, mainly villages and hamlets) Castionetto and Casacce.