Leopold (German: Luitpold), known as Leopold the Generous (German: Luitpold der Freigiebige), was Margrave of Austria as Leopold IV from 1136, and Duke of Bavaria as Leopold I from 1139 until his death in 1141.
He was one of the younger sons of Margrave Leopold III, the Holy. It is not known why he was originally preferred to his brothers Adalbert and Henry Jasomirgott.
Through his mother Agnes, he was related to the Hohenstaufen. In the course of their struggle against the competing Welfen family, he was given the formerly Welfish Bavaria as a fief by Emperor Conrad III. He managed to maintain his position there, as his brother Otto was Bishop of Freising there.
The most important measure of his short reign was the Exchange of Mautern entered into with the Bishop of Passau in 1137. The bishop was given the St. Peter's Church in Vienna, while the Margrave received extended stretches of land from the bishop outside the city walls, with the notable exception of the territory where a new church was to be built, which was to become St. Stephen's Cathedral.
Leopold died at Niederaltaich Abbey in Bavaria unexpectedly and was succeeded by his brother Henry.