Fennoscandia, or the Fennoscandian Peninsula, is the geographical peninsula in Europe which includes the Scandinavian and Kola peninsulas, mainland Finland, and Karelia. Administratively, this roughly encompasses the mainlands of Finland, Norway and Sweden, as well as Murmansk Oblast, much of the Republic of Karelia, and parts of northern Leningrad Oblast in Russia.

A peninsula is a landform that extends from a mainland and is surrounded by water on most sides. Peninsulas exist on all continents. The largest peninsula in the world is the Arabian Peninsula.