Colonno is a comune (municipality) in the Province of Como in the Italian region Lombardy, located about 50 kilometres (31 mi) north of Milan and about 15 kilometres (9 mi) northeast of Como. As of 31 December 2004, it had a population of 557 and an area of 5.7 km².

Colonno borders the following municipalities: Argegno, Laino, Lezzeno, Ossuccio, Pigra, Ponna, Sala Comacina.