Gavlfjorden is a fjord (more accurately, a sound) in Nordland county, Norway. The 20-kilometre (12 mi) long fjord separates the large islands of Langøya and Andøya in the Vesterålen archipelago and it runs along the border of three municipalities: Øksnes, Andøy, and Sortland. In the north, the fjord flows out into the Norwegian Sea, and in the south, the fjord splits into the Sortlandssundet strait and the Risøysundet strait.