Wahlenbergfjorden, sometimes known in English as Waalenburg Bay, is a fjord on the southwest coast of the Arctic island of Nordaustlandet, in Norway's Svalbard archipelago. At 46 kilometres (29 mi) in length, and 15 km (9.3 mi) wide, it is the fifth longest fjord in the archipelago, and the longest on the island. The fjord lies between Gustav V Land and Gustav Adolf Land, at geographical co-ordinates (79°40′N20°00′E).