Karasor (; ) is a salt lake in the Ekibastuz City Administration, Pavlodar Region, Kazakhstan.
Karasor is the largest of the lakes in the area surrounding Ekibastuz. It is located to the northeast of the city and to the west of Kalkaman.
Karasor is an endorheic lake in the Irtysh Basin. It stretches from southeast to northwest for roughly and is about wide. Smaller lake Shandaksor, with the Ekibastuz GRES-2 Power Station rising by its eastern shore, lies to the west of the northwestern corner, and Zhyngyldy, with the Ekibastuz GRES-1 Power Station by its northern shore, lies to the WSW of the southwestern lakeshore. Other lakes in the vicinity are Tuzdysor, located to the northwest, Kudaikol to the southeast, Atygay to the SSW, and Shureksor to the north.
The Bala Tundik river flows into Karasor. The lake is fed by snow and rain. Karasor usually freezes in November and thaws in April. The lakeshores are flat and the surrounding area is used for local livestock grazing. There are also some cultivated fields.
Large quantities of ash are dumped into lake Karasor by the two neighboring power plants. The accumulation of dumped ashes in the southern part of the lake forms an island or peninsula with an average diameter of . The ashes are collected by people of the neighboring villages in order to sell them to be recycled for the industrial production of aluminosilicate microparticles.