Hedrum is a former municipality in Vestfold county, Norway. The 264-square-kilometre (102 sq mi) municipality existed from 1838 until its dissolution in 1988. The area is now part of Larvik Municipality. The administrative centre was the village of Nanset (from 1978-1988; prior to that, the municipal administration was located in the village of Hedrum where the Hedrum Church is located). Other villages in Hedrum include Gjone, Kvelde, Skinmo, and Verningen.^[4]

Hedrum municipality was located in the Lågendalen valley, the lower part of the valley that follows the river Numedalslågen. The valley is relatively flat and dominated by agricultural areas. The valley is surrounded by wooded hills which rise up towards 500-metre (1,600 ft) tall mountain peaks. Among other things, the area is known for potato cultivation and fishing.^[5]

The parish of Hedrum was established as a municipality on 1 January 1838 (see formannskapsdistrikt law). Over the years, there have been many municipal border adjustments. On 1 January 1875, an area of Hedrum (population: 46) became part of the neighboring town of Larvik. On 1 January 1878, an area of Hedrum (population: 61) became part of the neighboring municipality of Andebu. On 1 January 1891, an area of Tjølling municipality (population: 11) became part of Hedrum. In 1937, an area of Hedrum (population: 69) became part of the neighboring town of Larvik. In 1948, an area of Hedrum (population: 296) became part of the neighboring town of Larvik.^[6]

During the 1960s, there were many municipal mergers across Norway due to the work of the Schei Committee. On 1 January 1964, two border adjustments were made in Hedrum. One area of Hedrum (population: 16) was transferred to Siljan Municipality (in Telemark county) and the adjacent Bakke area (population: 75) was transferred to Porsgrunn Municipality (also in Telemark county). On 1 January 1968, the unpopulated Svartangen area of Siljan was transferred to Hedrum (and Vestfold county). On 1 January 1974 the unpopulated Tagtvedt area of Hedrum was transferred to the neighboring town of Larvik. On 1 January 1983, the unpopulated Bergan area of Hedrum was transferred to the neighboring Lardal municipality. On 1 January 1986, part of the Åsveien 3 property in Hedrum was transferred to the neighboring town of Larvik. On 9 January 1987 an unpopulated area in northern Hedrum was transferred to Lardal municipality.^[6]

On 1 January 1988, the municipality was dissolved as part of a major municipality merger which consolidated the municipalities of Brunlanes (population: 8,138), Hedrum (population: 10,449), and Tjølling (population: 7,878) with the towns of Larvik (population: 8,045) and Stavern (population: 2,538) to create a new, much larger Larvik Municipality with a population of 37,048 people.^[6]

While it existed, this municipality was responsible for primary education (through 10th grade), outpatient health services, senior citizen services, unemployment, social services, zoning, economic development, and municipal roads. During its existence, this municipality was governed by a municipal council of directly elected representatives. The mayor was indirectly elected by a vote of the municipal council.^[13]

• List of former municipalities of Norway