Chatyr-Köl (Kyrgyz: Чатыр-Көл, Russian: Чатыр-Куль, romanized: Chatyr-Kul') is an endorheic alpine lake in the Tian Shan mountains in At-Bashy District of Naryn Province, Kyrgyzstan; it lies in the lower part of Chatyr-Köl Depression near the Torugart Pass border crossing into China. The name of the lake means “Celestial Lake” in Kyrgyz (literally "Roof Lake").

The mean annual temperature in the lake basin is −5.6 °C (21.9 °F), with mean temperature of −22 °C (−8 °F) in January, and 7.1 °C (44.8 °F) in July. The maximum temperature in summer is 24 °C (75 °F), and the minimum one in winter is −50 °C (−58 °F). Some 88-90% of the lake basin's 208–269 mm of annual precipitation falls in summer. From October to end of April the lake surface freezes, the ice becoming as much as 0.25-1.5 m thick.

The water of Chatyr Kul Lake is yellowish-green with water transparency of up to 4 metres (13 ft). The mineralization of the lake ranges from 0.5 to 1.0 milligrams per liter (chloride, hydrocarbonate, sodium and magnesium type of mineralization). The salinity of the lake is 2 ppt. Mineral sources in the south part of the lake have mineralization of from 5 to 7 grams (0.18 to 0.25 oz) per liter and pH = 5,8-6,0. Flow rate is 1,866 m (65,900 cu ft) in winter and 3,629 cubic metres (128,200 cu ft) during summer. 41 small streams debouches into the lake, of those 21 originate in Torugart Range and 20 - in Atbashy Range.

Negative water balance of the lake over the last decades causes the decline in the lake level. The mineral water from the sources is cold and has a strong mineral taste and flow first into the small Chatyr Kul lake that is about 1,5 meters higher than the actual Chatyr Kul.

Since 1998, a section of the lake and its shore (3,200 ha land, 3,954 ha water) is protected as part of the Karatal-Japyryk Nature Reserve. The whole lake has been a game reserve (IUCN category IV) since 1972. The game reserve was established to protect water fowl, including the bar-headed goose. The lake is a Ramsar site of globally significant biodiversity (Ramsar Site RDB Code 2KG002).

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  Map of the region including the Ozero Chatyr-Kul' (AMS, 1948)
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  Map of the region including the Ozero Chatyr-kel' (DMA, 1985)