Lenvik (Northern Sami: Leaŋgáviika) is a former municipality in Troms county, Norway. The municipality existed from 1838 until its dissolution in 2020. The municipality was partly situated on the mainland and partly on the island of Senja in what is now Senja Municipality. The administrative centre was the town of Finnsnes, where the Gisund Bridge connects Senja to the mainland on Norwegian County Road 86. Other villages in the municipality included Aglapsvik, Gibostad, Botnhamn, Fjordgård, Finnfjordbotn, Husøy, Langnes, Laukhella, Silsand, and Rossfjordstraumen.

Prior to its dissolution in 2020, the 893-square-kilometre (345 sq mi) municipality was the 126th largest by area out of the 422 municipalities in Norway. Lenvik was also the 101st most populous municipality in Norway with a population of 11,679. The municipality's population density was 13.1 inhabitants per square kilometre (34/sq mi) and its population has increased by 4.2% over the previous decade.

The parish of Lenvik was established as a municipality on 1 January 1838 (see formannskapsdistrikt law). In 1848, most of the mainland parts of Lenvik (population: 2,616) were separated to form the new Målselv Municipality, leaving Lenvik with 3,029 residents. Then in 1855, the northern part of Lenvik (population: 811) was separated to form the new Hillesøy Municipality. This left Lenvik with 2,757 inhabitants. On 1 January 1871, a small part of Lenvik (population: 70) was transferred to the neighboring Malangen Municipality.

During the 1960s, there were many municipal mergers across Norway due to the work of the Schei Committee. On 1 January 1964, the following areas were merged into Lenvik:

• the part of Sørreisa Municipality on the island of Senja (population: 129)
• the Hellemo, Paulsrud, Johnsgård, and Stormo farms in Tranøy Municipality (population: 106)
• the part of Hillesøy Municipality on the island of Senja and the whole island of Hekkingen (population: 1,159)

These areas joined to old areas of Lenvik to form a new, larger Lenvik Municipality with a total population of 10,219.

In March 2017, the Parliament of Norway voted to merge Berg Municipality, Torsken Municipality, Lenvik Municipality, and Tranøy Municipality. The new municipality would encompass the whole island of Senja plus part of the mainland located between the Gisundet strait and the Malangen fjord. On 1 January 2020, Lenvik Municipality ceased to exist when it became part of the new Senja Municipality.

The municipality (originally the parish) is named after the old Lenvik farm (Old Norse: Lengjuvík) since the first Lenvik Church was built there. The first element is the genitive case of the river name Lengja. The river name is derived from the word langr which means "long". The last element is vík which means "cove" or "bay". Historically, the name of the municipality was spelled Lenviken. On 6 January 1908, a royal resolution changed the spelling of the name of the municipality to Lenvik, removing the definite form ending -en.

The coat of arms was granted on 22 August 1986 and it was in used until 1 January 2020 when the municipality became part of the new Senja Municipality. The official blazon is "Azure, three oars bendwise Or, blades to the chief" (Norwegian: I blått tre skråstilte gull årer med bladene opp). This means the arms have a blue field (background) and the charge is three oars laying diagonally with the blades at the top of the shield. The oars have a tincture of Or which means they are commonly colored yellow, but if it is made out of metal, then gold is used. The blue color in the field and the oars were chosen as a symbol for sailing and shipping along with the fishing industry which is the main form of income in the municipality. The arms were designed by Arvid Sveen.

The Church of Norway had one parish (sokn) within Lenvik Municipality. It was part of the Senja prosti (deanery) in the Diocese of Nord-Hålogaland.

Churches in Lenvik

Parish (sokn)	Church name	Location of the church	Year built
Lenvik	Finnsnes Church	Finnsnes	1979
	Lenvik Church	Bjorelvnes	1879
	Rossfjord Church	Rossfjordstraumen	1822
	Fjordgård Chapel	Fjordgård	1976
	Gibostad Chapel	Gibostad	1939
	Husøy Chapel	Husøy i Senja	1957
	Lysbotn Chapel	Lysnes	1970
	Sandbakken Chapel	Sandbakken	1974

The first local church was built around the year 1150 at Bjorelvnes, and for a century, this was the northernmost church in the world. Important villages in the past include Klauva and Gibostad. Gibostad was the administrative centre until the 1960s, when the administration was moved to Finnsnes. In 2000, Finnsnes was declared a town.

Lenvik Municipality was partly located on the island of Senja and also on the mainland of Norway. The Malangen fjord flowed along the northern boundary and the Solbergfjorden was located along the southern boundary. The Gisundet strait ran north–south through the center of the municipality with only one road crossing, the Gisund Bridge. The neighboring Berg Municipality and Tranøy Municipality bordered the municipality to the west, Tromsø Municipality was to the north (across the Malangen fjord), Balsfjord Municipality and Målselv Municipality were to the east, and Sørreisa Municipality and Dyrøy Municipality were to the south (across the Solbergfjorden). The highest point in the municipality was the 1,202.8-metre (3,946 ft) tall mountain Vassbruntinden. The lake Lysvatnet was located in the municipality on Senja island, west of Gibostad.

While it existed, Lenvik Municipality was responsible for primary education (through 10th grade), outpatient health services, senior citizen services, welfare and other social services, zoning, economic development, and municipal roads and utilities. The municipality is governed by a municipal council of directly elected representatives. The mayor is indirectly elected by a vote of the municipal council. The municipality falls under the Senja District Court and the Hålogaland Court of Appeal.

The municipal council (Kommunestyre) of Lenvik was made up of 31 representatives that were elected to four year terms. The tables below show the historical composition of the council by political party.

The mayor (Norwegian: ordfører) of Lenvik is the political leader of the municipality and the chairperson of the municipal council. Here is a list of people who have held this position (incomplete list):

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  View from Gibostad village on Senja island towards Kistefjellet mountain on the mainland
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  View of Botnhamn
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  View of Trollvik

• List of former municipalities of Norway