Lavangen (Loabák) is a municipality in Troms og Finnmark county, Norway. The administrative centre of the municipality is the village of Tennevoll. Other villages in Lavangen include Fossbakken and Spansdalen (in the inland areas) and Kjeiprød, Røkenes, Låternes, Tennevoll, Hesjevika, Soløy, and Å (surrounding the fjord).
The municipality is the 266th largest by area out of the 356 municipalities in Norway. Lavangen is the 334th most populous municipality in Norway with a population of 970. The municipality's population density is and its population has decreased by 4.5% over the previous 10-year period.
Lavangen was established on 1 January 1907 when it was separated from Ibestad Municipality. The initial population was 1,536. During the 1960s, there were many municipal mergers across Norway due to the work of the Schei Committee. On 1 January 1964, the neighboring municipalities of Lavangen (population: 1,677) and Salangen (population: 2,611) were merged into one large municipality of Salangen. The merger was brief, however, because on 1 January 1977, the old Lavangen municipality (except for the Lavangsnes area) was made a separate municipality once again.
On 1 January 2020, the municipality became part of the newly formed Troms og Finnmark county. Previously, it had been part of the old Troms county.
The municipality is named after the local Lavangen fjord (Laufangr) since it is a central geographical feature of the area. The first element is lauf which means "leaf" (here in the sense of 'birchwood'). The last element is angr which means "fjord".
The coat of arms was granted on 18 December 1987. The official blazon is "Gules, three birch leaves Or in pall stems conjoined" (I rødt tre gull bjørkeblad forent i trepass). This means the arms have a red field (background) and the charge is three birch leaves that are connected and in a Y-shape design. The leaves have a tincture of Or which means they are commonly colored yellow, but if it is made out of metal, then gold is used.