Prestesteinsvatnet is a lake in Luster Municipality in Vestland county, Norway, with a small part of the lake crossing over into the neighboring Lom Municipality in Innlandet county. The 4.12 km2 lake sits at an elevation of 1357 m above sea level. It lies along the south side of the Sognefjellsvegen road, just to the north of the mountain Fannaråki and the Fannaråkbreen glacier. The lake sits just outside the borders of Jotunheimen National Park. The village of Skjolden lies about 20 km to the southwest of the lake.