Sør-Varanger is a municipality in the county of Finnmark, Norway.

Sør-Varanger is a vast area of some 3,700 km², situated between Finland and Russia. Most of the area is low-lying forest of pine and birch, with barren sections facing the Barents Sea.

The original inhabitants of the area are the eastern Sami, often called Skolt Sami. This Sami group migrated between coast and inland in present Norwegian, Finnish and Russian territory, long before any borders existed. In the 16th century, they were converted to the Russian Orthodox faith, and still today the chapel of Saint George at Neiden, dating from 1565, is a memory of eastern influence. In 1826, the previously disputed areas were divided between Norway and Russia (Finland being a Russian principality), causing great difficulties for the Sami. The Norwegian state also invited Norwegian settlers to come to the area, building lutheran churches to counterbalance the orthodox heritage. During the 19th century Finnish settlers arrived to the valleys, and from 1906 Norwegians came in numbers because of the iron mining starting up in Kirkenes.

The centre of Sør-Varanger is the town of Kirkenes. Other settlements include Bugøynes, Neiden and little hamlets along the river of Pasvikelva .

The flora of the area is a part of the Russian and Siberian taiga, including a few hundred spruce trees of the Russian variety. Bears also inhabit the upper valley, notably in the National Park of Øvre Pasvik.

The attractions in the area include the orthodox chapel of Saint George in Neiden, the chapel of King Oscar II in Grense Jakobselv on the Russian border (built in 1869 to mark the border) and prehistoric labyrinth constructions in the area, probably used for religious purposes.

The local airport is called Høybuktmoen which also is a military camp. Garnisonen i Sør-Varanger (GSV) is based at Høybuktmoen.

Popular leisure activities include salmon fishing in one of the numerous rivers, hunting for moose and grouse, and snowmobile driving. Many inhabitants also own and frequently use a cabin located in more remote parts of the municipality.