The Upper Sûre Lake (Luxembourgish: Stauséi Uewersauer; French: Lac de la Haute-Sûre [lak də la ot syʁ]; German: Obersauer-Stausee [ˈoːbɐˌzaʊɐ ˈʃtaʊˌzeː]) is a large reservoir in north-western Luxembourg.

Immediately above it, the river has been dammed to form a hydroelectric reservoir extending some 10 kilometres (6.2 mi) up the valley.

The valley of the Upper Sûre surrounding the reservoir has been designated as a Ramsar site, in Luxembourg and in neighboring Belgium, since 2004.

[3][4] Surrounded by luxuriant vegetation and peaceful creeks, the lake is a center for water sports, such as sailing, canoeing, and kayaking.

Such outdoor activities, which make it an attractive spot for tourists, has led to the growth of a local crafts industry.