Like the rest of Austria, Upper Austria is predominantly Roman Catholic. Approximately 7.2% of the population is of foreign origin, 53% of which is from former Yugoslavia. Other minority groups include those of Greek and Turkish origin.

As of the last census, which took place in 2001, the population of Upper Austria is 1,376,797. To the right are historical population figures of the state. Austrians of German mother tongue, by far the country’s largest group, form 91.1% of Austria’s population. The remaining number of Austria’s people is of non-Austrian descent, many from surrounding countries, especially from the former East Bloc nations.

The Austrian federal states of Carinthia and Styria are home to a significant Slovenian minority with around 14,000 members Austrian census; unofficial numbers of Slovene groups speak of about 40,000). So-called guest workers and their descendants also form an important minority group in Austria. Around 20,000 Hungarians and 30,000 Croatians live in the east-most Bundesland, Burgenland.