Saint Leopold III (German: Luitpold), known as Leopold the Good, was the Margrave of Austria from 1095 to his death in 1136. He was a member of the House of Babenberg. He was canonized on 6 January 1485 and became the patron saint of Austria, Lower Austria, Upper Austria, and Vienna. His feast day is 15 November.
Leopold was born at Babenberg castle in Gars am Kamp, the son of Margrave Leopold II and Ida of Formbach-Ratelnberg. The Babenbergs came to Austria from Bavaria where the family had risen to prominence in the 10th Century. He grew up in the diocese of Passau under the influence of the reformer Bishop Altmann of Passau.
In 1096 Leopold succeeded his father as margrave of Austria at the age of 23. Leopold called himself "Princeps Terræ", a reflection of his sense of territorial independence. He was considered a candidate in the election of the Kaiser of the Holy Roman Empire in 1125, but declined this honour.
In 1663, under the rule of his namesake Emperor Leopold I, he was declared patron saint of Austria instead of Saint Koloman.