Battle of Nesjar was a sea battle off the coast of Norway in 1016. It was a primary event in the reign of King Olav Haraldsson. Icelandic skald and court poet Sigvatr Þórðarson composed the poem Nesjavísur in memory of the battle. A monument known as the Nesjar Monument was erected on the 1000th anniversary of the battle, located in Helgeroa village in Larvik, Vestfold County, where the battle is believed to have occurred.