Ingelsvatnet or Ingjelsvatnet is a lake in the municipality of Lierne in Nord-Trøndelag county, Norway. The 7.16-square-kilometre (2.76 sq mi) lake lies only 1.5 kilometres (0.93 mi) from the south shore of the large lake Tunnsjøen and 10 kilometres (6.2 mi) west of the village of Tunnsjø senter. The water flows out through a series of small lakes and streams that lead into Tunnsjøen.