Köl-Suu () is an alpine lake in At-Bashi District of Naryn Province of southeastern Kyrgyzstan. It is located at 3500 m elevation in the Tian Shan mountains. It is fed and drained by the Kurumduk River, a left tributary of the Kök-Kyya River, which is a right tributary of the Toshkan River (Kakshal).