The Karakengir (; ), also known as Kengir, is a river in the Ulytau District, Ulytau Region, [Kazakhstan. It has a length of 295 km and a drainage basin of 18400 km2.

It is one of the most important tributaries of the Sarysu. The city of Zhezkazgan, the capital of Ulytau Region, is located by its banks. A reservoir was built close to the city at the time of the Kazakh SSR.