Sasykkol (Kazakh: Сасықкөл, Sasyqköl) is a lake in eastern Kazakhstan. It is located near 46°35′0″N 81°0′0″E / 46.58333°N 81.00000°E / 46.58333; 81.00000. It has a surface area of 600 km² (736 km² when water level is high), average depth of 3.3 m, and maximum depth of 4.7 m. Fishery on the lake is common. Water birds including the mute swan, whooper swan, and spoonbill can be found here.

Into the Sasykkol lake (translated from the Kazakh language "Sasyk" - rotten, fetid;" Kol " - lake), in the delta of the Alakol Biosphere Reserve, flows the Tentek river from the south. The average depth of the lake is about 3 m, and the maximum depth is 4.7 m. The average annual water level varies up to 60 cm due to the fact that the lake is flowing. Through the river Zhinishkesu water goes to Lake Koshkarkol and then flows into Lake Alakol. Since the water in the lake is fresh, its mineralization varies during the year from 0.27 to 2.16 g/L.

Lake Sasykkol is part of the Alakol Biosphere Reserve, designated by UNESCO as part of its Man and the Biosphere Programme in 2013.