Arctic naval operations of World War II were the World War II naval operations that took place in the Arctic Ocean, and can be considered part of the Battle of the Atlantic and/or of the European Theatre of World War II.
Pre-war navigation in the region focused on fishing and the international ore-trade from Narvik and Petsamo. Soviet settlements along the coast and rivers of the Barents Sea and Kara Sea relied upon summer coastal shipping for supplies from railheads at Arkhangelsk and Murmansk. The Soviet Union extended the Northern Sea Route past the Taymyr Peninsula to the Bering Strait in 1935. The Winter War of 1939-1940 between Finland and the Soviet Union opened the northern flank of the Eastern Front of World War II. The Arctic was initially dominated by the Soviet Northern Fleet of a few destroyers, with larger numbers of submarines, minesweepers, and torpedo cutters supported by icebreakers. The success of the 1940 German invasion of Norway provided the Kriegsmarine with naval bases from which capital ships might challenge units of the British Royal Navy Home Fleet. Luftwaffe anti-shipping aircraft of Kampfgeschwader 26 (KG 26) and Kampfgeschwader 30 (KG 30) operated intermittently from Norwegian airfields, while Küstenfliegergruppen aircraft including Heinkel He 115s and Blohm & Voss BV 138s undertook routine reconnaissance. Following the 1941 Axis invasion of the Soviet Union, the Allies initiated a series of Arctic convoys to bring military supplies to the Soviet Union in formations of freighters screened by destroyers, corvettes and minesweepers. Escorting cruisers typically maneuvered outside the formations, while a larger covering force including battleships and aircraft carriers often steamed nearby to engage Kriegsmarine capital ships or to raid the German naval bases in Norway.