Lake Tsimanampetsotsa (French: Lac Tsimanampetsotsa) is a saline lake in the Toliara Province, in the southwestern part of Madagascar. It is located at around 24°07′S 43°45′E / 24.117°S 43.750°E. The lake is an important wetland and is protected within a national park and as a Ramsar site. The Ramsar site has a total area of 456 km2 (176 sq mi), while the surface of the lake is much smaller. The lake Tsimanampetsotsa is a part of the Tsimanampetsotsa National Park.
The name of the lake in Malagasy means "lake without dolphins".