The ethnic Finns are the dominant ethnic group in Finland, and the largest ethnic minority in Sweden, the Sweden-Finns. An indigenous minority of ethnic Finns also live in Norway, the Kvens.

Ethnic Finns share a common language and culture, although it is common to make a sub-division between Eastern and Western Finns. The Eastern Finns are more influenced by Karelian cultural traits, while the Western Finns are more influenced by Finland-Swedish and Scandinavian culture and language. Historically, the Tavastian tribe was the most prominent among the Western Finns.

It's a matter of definition whether the Karelians are to be counted as part of the more narrow concept Ethnic Finns or to the wider concept of Finnic peoples. As a legacy of the important Fennoman Movement, Karelians are thought of as the "purest source" for Finnishness, particularly East Karelians — but religiously the East Karelians are Russian Orthodox while the Finns in Finland and Scandinavia are of Lutheran faith.

Also the Ingrian Finns are Lutherans, which may have contributed to their survival as an ethnos of their own despite harsh treatment in Stalinist and post-Stalinist Soviet Union, contrary to that of the Finnic Izhorians of Ingria. Many of the Ingrian Finns descend from 17th century settlers arriving in Ingria from Savonia and Finnish Karelia, which may speak for including them among the ethnic Finns.

The Sami people are seen neither as ethnic Finns nor as Finnic, but as one of the more distantly akin Finno-Ugric peoples. The chief distinction made by the Finns is that the Finnic culture is traditionally an agrarian culture — and north of the Gulf of Finland, one dominated by small distantly located farms — while the Sami culture is thought of as traditionally (Pastoralist) nomadic, living and moving in larger extended families. The (Baltic-) Finnic languages are not mutually intelligible with Sami languages — both grammar and vocabulary are too different; while Finnish often has expanded its vocabulary using neologisms, Sami languages more often use loanwords.

Old Norse is believed not to make the distinction between Samis and the Finnics of Finland and Balticum, which still cause some confusion as the Norwegian word Finn denotes Samis.