Botkul (Kazakh: Боткөл; Russian: Боткуль) is a bittern salt lake in the Kazakhstan–Russia border.

Its waters have a bitter, stinging taste and a strong smell of hydrogen sulfide.

The authorities are exploring the potential of developing Botkul as a tourist attraction.

The main river feeding its waters is the Solyonaya, a small stream flowing from the west.

The western part of the lake lies in Pallasovsky District, Volgograd Oblast, Russian Federation and the eastern in Bokey Orda District, West Kazakhstan Region, Kazakhstan.