Tianchi () is an alpine lake in Xinjiang, Northwest China, situated at . The name (天池) literally means "Heaven Lake" or "Heavenly Lake" and can refer to several lakes in mainland China and Taiwan. This Tianchi lies on the north side of the Bogda Shan range of the Tianshan Mountains, about south of Fukang City and east (straight-line distance) of Ürümqi. (Bogda is a Mongolian word, meaning "God".) It is an alpine drift lake shaped in the Quaternary Glacier period.
The lake is above sea level, covering , deep at the deepest point.
In 2006, it was designated for four years of restoration work at a cost of 800 million yuan (US$100 million). The plan calls for the tourism area around the lake to be increased from the present 158 km² to 548 km².
The lake is accessible by Provincial Highway 111 from Fukang City.