The municipality of Elsfjord was established on 1 July 1929 when the large Hemnes Municipality was divided into three separate municipalities: Elsfjord (population: 765), Hemnes (population: 1,077), and Sør-Rana (population: 1,708). During the 1960s, there were many municipal mergers across Norway due to the work of the Schei Committee. On 1 January 1962, the municipality of Elsfjord (population: 920) was merged with the neighboring municipalities of Drevja (population: 1,001) and Vefsn (population: 5,358) and with the town of Mosjøen) to form a new, larger Vefsn Municipality.
