Flesberg is a municipality in Buskerud county, Norway. It is part of the traditional region of Numedal. The administrative centre of the municipality is the village of Lampeland.The economy of Flesberg is dominated by forestry and agriculture, as well as the cluster of high-tech industries in neighbouring town of Kongsberg.
The municipality (originally the parish) is named after the old Flesberg farm (Old Norse: Flesberg), since the first church was built here. The first element is fles which means "rock" and the last element is Berg which means "mountain".The coat-of-arms is from modern times. They were granted on 10 March 1989. The arms show two tømmerklaver to represent forestry - and also the letter F.