Langvatnet[2] is a lake in Rana Municipality in Nordland county, Norway.

The 26.38-square-kilometre (10.19 sq mi) lake lies just northwest of the town of Mo i Rana.

The lake flows out into the river Langvassåga just north of Mo i Rana Airport, Røssvoll.

The lake used as a reservoir for the Langvatn hydroelectric power plant in the village of Ytteren, just down the hill from the lake.

This article related to a lake in Nordland in Norway is a stub.