Finnskogen () is a forest area of Norway and Sweden situated in the counties of Innlandet and Värmland respectively, so named because of immigration of Finnish people in the 17th century, the so-called Forest Finns ().
The core area of Finnskogen lies in the eastern part of a small region known as Solør, on the border with Sweden. It consists of a forested belt of land, about wide going through the present-day municipalities of Våler, Åsnes, Grue, and Kongsvinger. It is adjacent to the Swedish region with similar Finnish immigration, named Finnskogarna.
More were encouraged to come to Sweden during the reign of Gustavus Adolphus (1611–1632).
Their loyalties during the Hannibal War (1643–1645) were with Sweden and some were caught spying on Norwegian troops.