The Valchiavenna (Italian: [valkjaˈvɛnna]; Lombard: Valciàvena [ʋaltʃaˈʋɛna]) is an alpine valley in the Province of Sondrio , in Lombardy in northern Italy. It lies to the north of Lake Como , and is traversed by the rivers Mera and Liro. It can be divided into three parts which branch from the confluence of these rivers near Chiavenna , the principal town of the region.

The lower part, the Bassa Valchiavenna, follows the course of the Mera downstream through the Piano di Chiavenna to Lago di Mezzola , and continues across the Pian di Spagna to the Trivio di Fuentes near Colico . Its territitory lies within the comuni of Mese, Prata Camportaccio , Gordona , Samolaco , Novate Mezzola and Verceia .

The northern part consists of the Valle Spluga , the valley of the Liro river which leads up to the Splügen Pass on the border with Switzerland and includes the comuni of San Giacomo Filippo , Madesimo , and Campodolcino .