Leopold I (c. 1290 – 28 February 1326),[1] called The Glorious, was Duke of Austria and Styria – as co-ruler with his elder brother Frederick the Fair – from 1308 until his death.

After the death of his eldest brother Duke Rudolph III in 1307 and the assassination of King Albert in 1308, Leopold became administrator of Further Austria, where he started a retaliation campaign against his father's murderers.

In 1311, he helped to suppress a Guelph uprising in Milan under Guido della Torre, and to lay siege to the city of Brescia.

The parleys failed and Leopold continued to attack the Bavarian forces of Louis, who unsuccessfully laid siege to the Swabian town of Burgau in 1324.

After the king had failed to reach the approval of his election by Pope John XXII and was even banned, he released Frederick in 1325.