Reschensee (German: [ˈʁɛʃn̩ˌzeː] ⓘ; Austrian German pronunciation: [ˈrɛʃn̩ˌseˑ]; Italian: Lago di Resia [ˈlaːɡo di ˈrɛːzja]) or Lake Reschen is an artificial lake in the western portion of South Tyrol, Italy, approximately 2 km (1 mi) south of the Reschen Pass, which forms the border with Austria, and 3 km (2 mi) east of the mountain ridge forming the border with Switzerland.

Its surface area of 6.6 km2 (2.5 sq mi) makes it also the largest lake above 1,000 m (3,300 ft) in the Alps.

The lake is famous for the steeple of a submerged 14th-century church; when the water freezes, this can be reached on foot.

In reality the bells were removed from the tower on July 18, 1950, a week before the demolition of the church nave and the creation of the lake.

The creation of the dam started in April 1940 pursuant to this second plan but, due to the war and local resistance, did not finish until July 1950.