Tsongmo Lake or Changu Lake is a glacial lake in the East Sikkim, India, some 40 kilometres (25 mi) away from Gangtok at altitude of 3,780 m (12,400 ft).

The road to Nathu La passes the lake on north side. The Chinese border crossing is only some 5 kilometres (3.1 mi) east-northeast in a straight line, but some 18 kilometres (11 mi) by road.

Indian Postal Service released a commemorative stamp on the lake on 6 November 200