Barents Sea (Russian, Barentsovo More), arm of the Arctic Ocean, named after its discoverer, the Dutch navigator Willem Barents. The sea is bounded on the west by the Norwegian archipelago of Svalbard and on the east by the two islands of Novaya Zemlya, which belong to Russia. The sea extends north from Norway and Russia for about 1,450 km (900 mi), and is bounded on the north by Franz Josef Land (Zemlya Frantsa Iosifa). Most of the coastline is rock and stone; high cliffs and fiords punctuate the western mainland coast, shallow bays and inlets lie on the eastern mainland coast, and glaciers plunge into the sea from the steep coasts of the northern archipelagos. The sea is shallow and large parts freeze during the winter because of the subarctic climate, but warm waters from the Gulf Stream keep a shipping lane open year-round along the coast to the Russian port of Murmansk. Trawlers from northern European ports fish its waters for cod and haddock.

During World War II the Barents Sea served as an important traffic route; it provided the only surface approach to the Union of Soviet Socialist Republics (USSR) from the west, when Mediterranean and overland routes were inaccessible. At present it forms the westernmost part of the 8,050-km (5,000-mi) seaway leading around the Russian coast from Murmansk in Europe to Vladivostok on the Pacific Ocean.