Suldalsvatnet (English: Lake Suldal) is the sixth-deepest lake in Norway. The 376-metre (1,234 ft) deep lake lies in the municipality of Suldal in Rogaland county, Norway. The 29-square-kilometre (11 sq mi) lake is the headwaters of the river Suldalslågen and it sits at an elevation of 69 metres (226 ft) above sea level. The lake has a volume of 4.51 cubic kilometres (1.08 cu mi).

The 29-kilometre (18 mi) long lake is regulated for use in two nearby hydroelectric power plants.