The Adige (Italian: Adige Italian pronunciation: [ˈaːdidʒe]; Venetian: Àdexe; German: Etsch; Ladin: Adesc; Latin: Athesis) is a river with its source in the Alpine province of South Tyrol near the Italian border with Austria and Switzerland. At 410 kilometres (250 mi) in length, it is the second longest river in Italy, after the River Po with 652 kilometres (405 mi).

The river flows out of the artificial Alpine Reschensee, located at the Reschen Pass (1,504 metres (4,934 ft)) close to the borders with Austria and Switzerland above the Inn valley. The lake is known for the church tower that marks the site of the former village of Alt Graun ("Old Graun") that was abandoned and flooded in 1953 when the dam enclosing the headwaters was finished. Near Glurns, the River Rom from the Swiss Val Müstair joins.

The Adige then runs eastbound through the Vinschgau to Merano where it is met by the Passer river from the north. The section between Merano and Bolzano is called Etschtal. South of Bolzano, the Eisack joins the river that is now heading south through a valley that always has been one of the major routes through the Alps, leading to and from the Reschen Pass and the Brenner Pass, at 1,370 metres (4,490 ft) considered the easiest of the main Alpine passes.