Askjelldalsvatnet is a lake in the municipality of Vaksdal in Hordaland county, Norway. The lake lies at an elevation of 805 metres (2,641 ft) in the Vikafjell mountains between the valleys of Modalen and Eksingedalen. The 2.84-square-kilometre (1.10 sq mi) lake has a dam at the southern end of the lake. The dam is used to regulate the water level so that the water can be used for hydro-electric power at a nearby power plant.