Zheltau () is a salt lake in Zerendi District, Akmola Region, Kazakhstan.
The lake lies To the SSE of the town of Kokshetau.
Zheltau lies in a tectonic depression of the Kazakh Uplands nearly to the west of the Kokshetau Hills, to the west of lake Zhamantuz and to the ENE of lake Zerendi. Zheltau village, former Oktyabr, is located to the north, close to the northern lakeshore.