For a long period of the Middle Ages, much of what would become Upper Austria constituted Traungau, a region of the Duchy of Bavaria.

(At the time, the term "Upper Austria" also included Tyrol and various scattered Habsburg possessions in southern Germany.)

By the end of 2022, the proportion of Catholics has decreased to 58.9%, and around 3% of the population were members of Austria’s national Lutheran church.

The Soviet and American armies occupied Upper Austria as hundreds of thousands of people fled from both sides of the land front.

[7]The Gross domestic product (GDP) of the state was 65.9 billion € in 2018, accounting for 17.1% of the Austria's economic output.

In its constitution, Upper Austria also declares its support for a united Europe that is committed to democratic, constitutional, social and federal principles as well as the principle of subsidiarity, preserves the autonomy of the regions and ensures their participation in European decision-making.

Historically, Upper Austria was traditionally divided into four regions: Hausruckviertel, Innviertel, Mühlviertel, and Traunviertel.