The Karmsund is a strait between the island and mainland Norway Karmøy in Haugesund. Since 1955, the Karmsundbrücke leads across the Sound.
The waterway along the Karmøy of Skudeneshavn in the south to Karmsund also bears the name Nordvegen ( northern route ), because it was the only connection along the coast in ancient times. From her country Norway got its name.
The Karmsund still plays an important role as a waterway, as the sea west of Karmøy is considered difficult to pass. Along the Karmsundes are industrial companies, shipping companies and ports for fisheries and industry.
The three highest electricity poles Norway are located at Karmsund, their height is 143.5 meters.
Karmsund is also the name of a local newspaper.