Brønnøysund is a town and the administrative centre of Brønnøy Municipality in Nordland county, Norway. The 3.38-square-kilometre town has a population of 5,093 and a population density of 1,507 inhabitants per square kilometre. It is also a former municipality within Nordland county. The village of Brønnøysund originally was declared a ladested in 1923 which made it an independent municipality. After merging with Brønnøy Municipality in 1964, it lost its town status.