Tongtiandong (Chinese: 通天洞, Tōngtiāndòng) is an archaeological site in the Xinjiang Autonomous Region of China, just to the south of the Altai mountains. The site had hunter-foraging human activity circa 40,000 BP (the Mousterian cultural layer was radiocarbon dated to approximately 46,000–44,000 BP, calibrated).

Until the discovery of Tongtiandong, the typical Mousterian techno-complex had not been identified in China, but the whole reduction sequence of the Mousterian techno-complex has now been identified in Tongtiandong cave.

From Tongtiandong and other sites, a general distributional pattern of different techno-complexes between Mongolia-Siberia and northern China can be established, for the dates between 50,000 and 32,000 cal BP.