Vefsn (Southern Sami: Vaapste) is a municipality in Nordland county, Norway.

In 1939, a small area of Vefsn Municipality (population: 45) was transferred to neighboring town of Mosjøen.

On 3 November 1917, a royal resolution changed the spelling of the name of the municipality to Vefsn.

The official blazon is "Sable, a rooster argent armed gules" (Norwegian: På svart bunn en sølv hane).

The rooster has a tincture of argent which means it is commonly colored white, but if it is made out of metal, then silver is used.

The municipal council (Kommunestyre) of Vefsn is made up of 29 representatives that are elected to four year terms.

The tables below show the current and historical composition of the council by political party.

Here is a list of people who have held this position:[33] The administrative centre of Vefsn is the town of Mosjøen which is situated along the innermost part of the Vefsnfjorden.

Outside Mosjøen, the large municipality of Vefsn is dominated by spruce forests, mountains, lakes, agriculture, and the Vefsna river.

There are many large lakes in Vefsn including Drevvatnet, Finnknevatnet, Fustvatnet, Hundålvatnet, Luktvatnet, Mjåvatnet, and Ømmervatnet.

The municipalities of Mosjøen, Elsfjord, and Drevja were incorporated into Vefsn in 1962, and are not included in these maps.

Tellingskrets 5, Granli; 6 Øvre Svenningdal, and 7 Austervefsen og Feplingdal, are now part of other municipalities, primarily Grane.

This tradition began to change in the mid to late 19th century, and inherited surnames were codified into law in 1923. Notable people that were born or lived in Vefsn include: