The Austrian Empire (Kaisertum Österreich) was a modern era successor empire founded on a remnant of the Holy Roman Empire centered on what is today's Austria that officially lasted from 1804 to 1867. It was followed by combining the Royal House with that of Hungary creating the dual monarchy Austria-Hungary (also known as the Austro-Hungarian Empire (1867 to 1918), which itself as one of the losers was dissolved at the end of World War I and broken into separate new states).

The term "Austrian Empire" is also used for the Habsburg possessions before 1804, which had no official collective name, although Austria is more frequent; the term has also been used, incorrectly, of Austria-Hungary.

The Austrian Empire was founded by the Habsburg monarch Holy Roman Emperor Francis II, (who became Emperor Francis I of Austria) as a state comprising his personal lands within the larger Empire.

This was a reaction to Napoleon Bonaparte's proclamation of the First French Empire in 1804.

Austria and some parts of the Holy Roman Empire then took the field against France and its German allies in the during the Third Coalition which lead to the crushing defeat at Austerlitz in early December 1805. By the fourth, the armies were in a cease fire in place and conducting peace talks nearby.

Subsequently, Francis II agreed to the humiliating Treaty of Pressburg (December 1805), which in practice meant dissolution of the long-lived Holy Roman Empire with a reorganization of the lost German territories under a Napoleonic imprint into a precursor state of what became modern Germany, those possessions nominally having been part of the Holy Roman Empire within the present boundaries of Germany, as well as other measures weakening Austria and the Habsburgs in other ways. Certain Austrian holdings in Germany were passed to French allies — the King of Bavaria, the King of Württemberg and the Elector of Baden. Austrian claims on those German states were renounced without exception.

One consequence of that was eight months later on 6 August 1806, Francis II dissolved the Holy Roman Empire, due to the formation of the Confederation of the Rhine by France; as he did not want Napoleon to succeed him. This action was unrecognized by George III of the United Kingdom who was also the Elector of Hanover who had also lost his German territories around Hanover to Napoleon. The English claims were settled by the creation of the Kingdom of Hanover which was held by George's British heirs until Queen Victoria's ascension, after which point it split into the British and Hanoverian royal families.

Although the office of Holy Roman Emperor was elective, the House of Habsburg had held the title since 1440 (with one brief interruption) and Austria was the core of their territories.

The Austrian Empire did not originally include the Kingdom of Hungary, and its extensive dependent territories, which the Habsburgs had ruled since 1541; Hungary was incorporated after the defeat of the revolutionaries during the 1848/49 revolution. Much controversy ensued, including Hungarian efforts to obtain constitutional reform by declining to crown the new Emperor Francis Joseph as King of Hungary, After Austria was defeated in the Austro-Prussian War of 1866, and left the German Confederation, the Austrian Empire was transformed into the Austro-Hungarian Empire by the Austro-Hungarian Compromise of 1867, which granted Hungary and the Hungarian lands equal status to the rest of Austria as a whole.