Duke Leopold III of Austria (November 1, 1351 – July 9, 1386) from the Habsburg family, was Duke of Austria from 1365 to 1379, and duke of Styria and Carinthia (Inner Austria) in 1365-1386.

Life
Born in Vienna, Leopold was a younger son of Duke Albert II, and younger brother of the Dukes Rudolf IV the Founder and Albert III. He first was the administrator of Tyrol, and was jointly charged with the rule of the Habsburg lands with Albert after Rudolf's death. However, by the Treaty of Neuberg of September 9, 1379, he became the exclusive ruler of Styria (including Wiener Neustadt), Carinthia, Carniola, the Windish March, Gorizia, the Habsburgs' possessions in Friuli, Tyrol and Further Austria. In 1368 he acquired Freiburg im Breisgau, in 1375 Feldkirch and in 1382 Trieste.
However, his attempts to expand his position in Switzerland and Swabia failed, when he died in the Battle of Sempach in 1386.