The House of Austria-Este (Italian: Casa d'Austria-Este; German: Haus von Österreich-Este), also known as House of Habsburg-Este (Italian: Casa d'Asburgo-Este; German: Haus von Habsburg-Este), is a noble house and cadet branch of the House of Este and the House of Habsburg, created in 1771 with the marriage between Duke Ferdinand of Habsburg-Lorraine and the Duchess Maria Beatrice d'Este, only daughter of the Duke of Modena Ercole III d'Este. After the death of Ercole III in 1803, the Este's direct line ended, and the Habsburg-Estes heired his possessions in Italy.
Ercole III d'Este, the last Este duke of Modena in the direct male line, was deposed in 1796 by the French as his Italian principality was incorporated into the Cisalpine Republic, later the Napoleonic Kingdom of Italy. In 1814 French rule in Italy ended. Modena was to be returned to his daughter Mary Beatrice d'Este and her son Archduke Francis of Austria-Este after Duke Ercole's death. Duke Ercole had been compensated with the duchy of Breisgau in southern Germany: the Habsburgs ceded this province to him, in anticipation of its falling eventually to the Habsburg family again, since Ercole's sole daughter was married to a cadet Habsburg, Archduke Ferdinand of Austria-Este. Duke Ercole died in 1803 and Breisgau was indeed inherited by his daughter and her husband, but they soon (1805) lost it to the expanding Grand Duchy of Baden.