Tianchi (Chinese: 天池; pinyin: Tiānchí, Uyghur: بوغدا كۆلى) is an alpine lake in Xinjiang, Northwest China.

This Tianchi lies on the north side of the Bogda Shan ("Mountain of God", Bogda is a Mongolian word meaning "God") range of the Tian Shan ("Mountain of Heaven"), about 30 kilometres (19 mi) south of Fukang and 45 kilometres (28 mi) east (straight-line distance) of Ürümqi.

The lake is classified as a highest level scenic area by the China National Tourism Administration.

The lake is the titular starting point of Vikram Seth's first book, From Heaven Lake: Travels Through Sinkiang and Tibet (1983), which describes his hitchhiking journey through Xinjiang, Qinghai, Tibet and Nepal to return home to India, during a break in his studies at Nanjing University in 1981.

Media related to Tianchi Lake of Tian Shan at Wikimedia Commons