Arstaddalsdammen is a lake that lies in the municipality of Beiarn in Nordland county, Norway. It is located about 15 kilometres (9.3 mi) southwest of the village of Moldjord. The 2.54-square-kilometre (0.98 sq mi) lake lies in the southern end of the Arstaddal valley, and it has a dam on the northern end. The dam was built in the 1960s.