Laguna del Sauce (Lagoon of the Willow) is a subtropical shallow lake[1] and the largest water body in the Maldonado Department of Uruguay.

[1] The closed ecosystem makes the lake prone to eutrophication, and has had regular algae blooms—one of which, in 2015, included cyanobacteria that disrupted water supplies.

A stream called Arroyo Potrero at the south end of the lagoon empties the water into the Río de la Plata at the beach of Chihuahua.

The Capitan Corbeta CA Curbelo International Airport is in the southwest coast of the lagoon, just east of the lake resort La Capuera.

[1][4] A 2021 analysis found that the lagoon's low lying geography and location would be effected by climate change in a number of ways, including: wetter weather, higher temperatures, season shift and more extreme precipitation events.