Karmøy is a municipality in Rogaland county, Norway. It is southwest of the town of Haugesund in the traditional district of Haugaland. The administrative centre of the municipality is the town of Kopervik.
Most of the municipality lies on the island of Karmøy. The island is connected to the mainland by the Karmøy Tunnel and the Karmsund Bridge. It is known for its industries, as well as for fishing. Karmøy is also well known in Norway for its beautiful heather moors and the white sand surfing beaches.
The municipality is the 294th largest by area out of the 356 municipalities in Norway. Karmøy is the 25th most populous municipality in Norway with a population of 42,541, making it one of the largest in the region. The municipality's population density is and its population has increased by 4.9% over the previous 10-year period. The island itself is the 4th most populated island in all of Norway.
The municipality of Karmøy is a recent creation. During the 1960s, there were many municipal mergers across Norway due to the work of the Schei Committee. On 1 January 1965, Karmøy municipality was created upon the merger of two towns and parts of five municipalities into one large municipality with 23,217 residents. The areas that were merged were:
the town of Kopervik (population: 1,737)
the town of Skudeneshavn (population: 1,275)
the whole municipality of Skudenes (population: 3,583)
the whole municipality of Stangaland (population: 2,678)
the whole municipality of Åkra (population: 6,008)
the part of the municipality of Avaldsnes located west of the Førresfjorden (population: 4,153)
most of the municipality of Torvastad (population: 3,783), except for the island of Vibrandsøy which went to Haugesund Municipality
The municipality is named after the island of Karmøy (Kǫrmt), since the majority of the municipality is located on this island. The first element is derived from the word karmr which means "bargeboard", likely in the sense of a "sheltering island". The last element, øy which means "island", was added later.