Montagna in Valtellina is a comune (municipality) in the Province of Sondrio in the Italian region Lombardy , located about 100 kilometres (62 mi) northeast of Milan and about 3 kilometres (2 mi) northeast of Sondrio.

Montagna in Valtellina borders the following municipalities: Caspoggio , Chiuro , Faedo Valtellino , Lanzada , Piateda , Poggiridenti , Ponte in Valtellina , Sondrio, Spriana , Torre di Santa Maria , Tresivio .