Nilsebuvatnet is a lake in the municipalities of Sandnes and Hjelmeland in Rogaland county, Norway. The 2.47 km2 lake lies in the Lyseheiane mountains about 13 km north of the village of Lysebotn and about 25 km east of the village of Årdal. The lake is regulated by a small dam on the southwest corner of the lake. The dam provides water for the Lysebotn power station. The lake drains out into the river Storåna which flows westward towards Årdal. The lake is accessible by a small service road from Lysebotn which leads up to the dam.