Aqköl (; ), is a salt lake in Zhangeldi District, in the SW sector of the Kostanay Region, Kazakhstan.
Local authorities try to promote tourism in the lake, but the area lacks the necessary infrastructure. The nearest inhabited locality is Akhmeta Baytursynuly to the east of the eastern shore.
Aqköl is located in the southern part of the Turgay Depression at above sea level. It is an endorheic lake sharing the same depression as smaller lakes and salt pans nearby. A projecting spit in the northwestern shore of the lake divides the northern side into two bays. The lake lies about to the NNE of the northern end of the Shalkarteniz lake. Much smaller lakes Uziqsor and Qaraqsor are located to the southeast, close to its shores. There is a hot spring from the lake where the water temperature reaches
long river Uly-Zhylanshyk flows into the northeastern shore of the lake.