Scandinavia is a historical and geographical region centered on the Scandinavian Peninsula in Northern Europe which includes the three kingdoms of Denmark, Norway and Sweden. The other Nordic countries, Finland, Iceland and the Faroe Islands, are also often included because of their close historic and cultural relations to Norway, Sweden, and Denmark.

In linguistics and cultural studies, the definition of Scandinavia is expanded to include the areas where Old Norse was spoken and where the North Germanic languages are now dominant. As a linguistic and cultural concept, Scandinavia thus also includes Iceland and the Faroe Islands.

As a cultural and historical concept, Scandinavia can include Finland as well (of the larger region Fenno-Scandinavia), often with reference to the nation's long history as a part of Sweden. Although Finland is culturally closely related to the other Scandinavian countries, the majority of Finns form a distinct linguistic and ethnic group, with a Finno-Ugric population that has incorporated features from both Eastern and Western Europe.

Since the Fennoman movement of the 1830s and political Scandinavism of the 1830s- 1850s,^[8] the inclusion of Finland and Iceland has divided opinions in the respective states. Although it depends on context which countries are considered Scandinavian, the term the Nordic countries is used unambiguously for Norway, Sweden, Denmark (including the Faroe Islands and Greenland), Finland (including Åland) and Iceland.

The Scandinavian Peninsula includes what is today mainland Sweden and mainland Norway. A small part of north-western Finland is sometimes also considered part of the peninsula. In physiography, Denmark is considered part of the North European Plain, rather than the geologically distinct Scandinavian peninsula mainly occupied by Norway and Sweden. However, Denmark has historically included the region of Scania on the Scandinavian Peninsula. For this reason, but even more for cultural and linguistic reasons, Denmark – Jutland on the Jutland peninsula of the European continent, along with Zealand and the other islands in the Danish archipelago – is considered part of the Scandinavian region also by the Scandinavians themselves.

The geography of Scandinavia is extremely varied. Notable are the Norwegian fjords, the Scandinavian Mountains, the flat, low areas in Denmark, and the archipelagos of Sweden and Norway. When Finland is included, the moraines (ice age remnants) and lake areas are also notable.

The climate varies from north to south and from west to east; a marine west coast climate (Cfb) typical of western Europe dominates in Denmark, southernmost part of Sweden and along the west coast of Norway reaching north to 65°N, with orographic lift giving more than 2000 mm/year precipitation (max 3500 mm) in some areas in western Norway. The central part - from Oslo to Stockholm - has a humid continental climate (Dfb), which gradually gives way to subarctic climate (Dfc) further north and cool marine west coast climate (Cfc) along the northwestern coast. A small area along the northern coast east of North Cape has tundra climate (Et) due to lack of summer warmth. The Scandinavian Mountains block the mild and moist air coming from the southwest, thus northern Sweden and Finnmarksvidda plateau in Norway receive little precipitation and have cold winters. Large areas in the Scandinavian mountains have alpine tundra climate.

In Finland, native Swedish speakers constitute a small, but influential, minority. All children are nonetheless taught Swedish at school. The ethnic nationalist Fennoman movement in Finland began to fight for equal language rights for Finnish-speakers from the Swedish-speaking elite in the 1830s. Its motto, "Swedes we are no longer/not, Russians we will never become, so let us be/become Finns" was popular among Finns. The movement's goal was to promote the equal legal status of the Finnish language in a country where the official language of government was Swedish or Russian, despite the large majority of the population being Finnish-speakers. The revival of the language spoken by the majority was symbolized by the creation of the national epos Kalevala and by a new reverence for the Finno-Ugric folk culture. The Fennomans protested against Finnish participation in the Scandinavian exhibition in Stockholm 1866, arguing that it would "enforce the impression that Finland belonged culturally to the Scandinavian realm" and imply that Finland did not have its own history before 1809 but was "first and foremost a periphery of western civilisation". The Fennoman movement met with resistance from the Svecoman movement and the Swedish elite. Finland Swedish author Zacharias Topelius joined in the criticism of the Fennoman movement in 1872, when a rhetorical question was posed by a peasant member of the Finnish parliament. The peasant parliamentarian referred to the often-mentioned claim that Finland was in debt to Sweden for its western civilization and he asked if anyone could show him the original promissory note of this debt. According to Dr. Henrik Meinander, Professor, Department of History, University of Helsinki, Finland, the rhetorical question was meant to emphasize that "Finns already stood on their own two feet and had bowed enough to the domestic Swedish-speaking elite." In response, Topelius wrote a poem arguing that the entire Finnish society was part of this promissory note. Finland's struggles and success in establishing a unique identity has been followed by scholars and journalists around the world.

The Russian Emperor Alexander II, Grand Duke of Finland, had issued a decree already in 1863 that would secure equal status for Finnish in public affairs within the following two decades, but only in 1902 did Finnish language finally receive an equal official status with Swedish and Russian. In Finland today, the only exception to the equality between Finnish and Swedish languages is made on the Åland islands, in favour of the Swedish language. According to the county legislation, the region is unilingually Swedish-speaking.

Finnish speakers constitute a minority in Sweden and Norway of similar relative size to the minority of Swedish speakers in Finland. There are also Finnic languages different from standard Finnish, known as Meänkieli in Sweden and Kven in Norway. The linguistic distance between the language families has often been seen by native speakers of each of these languages as indicative of a cultural distance, as well as a reason to consider the native Finnish speakers as a people separate from the Scandinavian culture group.

The modern usage of the term Scandinavia has been influenced by Scandinavism (the Scandinavist political movement), which was active in the middle of the 19th century, mainly between the First war of Schleswig (1848-1850), in which Sweden and Norway contributed with considerable military force, and the Second war of Schleswig (1864). In 1864, the Swedish parliament denounced the promises of military support made to Denmark by Charles XV of Sweden. The members of the Swedish parliament were wary of joining an alliance against the rising German power.

The Swedish king also proposed a unification of Denmark, Norway and Sweden into a single United Kingdom. The background for the proposal was the tumultuous events during the Napoleonic wars in the beginning of the century. This war resulted in Finland (formerly the eastern third of Sweden) becoming the Russian Grand Duchy of Finland in 1809 and Norway (de jure in union with Denmark since 1387, although de facto treated as a province) becoming independent in 1814, but thereafter swiftly forced to accept a personal union with Sweden. The dependent territories Iceland, the Faroe Islands and Greenland, historically part of Norway, remained with Denmark in accordance with the Treaty of Kiel. Sweden and Norway were thus united under the Swedish monarch, but Finland's inclusion in the Russian Empire excluded any possibility for a political union between Finland and any of the other Nordic countries.

The end of the Scandinavian political movement came when Denmark was denied the military support promised from Sweden and Norway to annex the (Danish) Duchy of Schleswig, which together with the (German) Duchy of Holstein had been in personal union with Denmark. The Second war of Schleswig followed in 1864, a brief but disastrous war between Denmark and Prussia (supported by Austria). Schleswig-Holstein was conquered by Prussia, and after Prussia's success in the Franco-Prussian War a Prussian-led German Empire was created, and a new power-balance of the Baltic sea countries was established.