Val Poschiavo (German: Puschlav(tal)) is a valley in the Italian-speaking part of the Swiss canton of Graubünden or Grisons. The main town is Poschiavo. It is bordered on the north by the Bernina Pass (Passo del Bernina) and on the south by the Italian border, with the Italian town of Tirano lying just across the border at the end of the valley. A branch of the narrow-gauge Rhaetian Railways from Tirano over the Bernina Pass into the St. Moritz region is the only rail link between Italy and eastern Switzerland - and is the highest-elevation rail route in Europe.
The two municipalities of Val Poschiavo, Poschiavo and Brusio, form the Bernina district of the canton. Towns, villages and hamlets in the valley, some bearing names in the local Lombard language, include: Miralago, Brusio, La Rasiga, Campascio, Zalende, Viano, Cavaione, Campocologno, Prada, San Carlo, Privilasco, Sant'Antonio, Annunziata, Pagnoncini, Cantone, Li Curt, Sfazù, Müreda, Motta, Cologna, Cavaglia, Pedecosta and Angeli Custodi.
Side valleys include: Val di Campo, Val dal Teo, Val Varuna, Val Saento. The valley is drained by Poschiavino river. Besides Lago di Poschiavo, the lakes in its basin are: Lago Bianco, Lago Braita, Lago Campascio, Lago Crocetta, Lago Dügural, Lago Matt, Lago Ombra, Lago Roan, Lago di Saoseo, Lago Teo, and Lago di Val Viola.