The Hardangerfjord is the fifth longest fjord in the world, and the second longest fjord in Norway. It is located in Vestland county in the Hardanger region. The fjord stretches 179 kilometres (111 mi) from the Atlantic Ocean into the mountainous interior of Norway along the Hardangervidda plateau. The innermost point of the fjord reaches the town of Odda.

In physical geography, a fjord or fiord is a long, narrow sea inlet with steep sides or cliffs, created by a glacier. Fjords exist on the coasts of Antarctica, the Arctic, and surrounded landmasses of the northern and southern hemispheres. Norway's coastline is estimated to be 29,000 km (18,000 mi) long with its nearly 1,200 fjords, but only 2,500 km (1,600 mi) long excluding the fjords.