Eiavatnet is a lake in Rogaland county, Norway. The 4.29 km2 lake is located on the border of the municipalities of Eigersund and Sokndal, about 15 km east of the town of Egersund. The lake is regulated at an elevation of 139 m so it can be used as a reservoir for the Lindland Power Station which is located a short distance north of Hauge in Sokndal. The lake Grøsfjellvatnet lies about 1 km north of this lake.