Burg am Leopoldsberg, Medieval castle on Leopoldsberg hill in Döbling, Austria.

Burg am Leopoldsberg is a medieval fortress that stands on a hilltop above the Danube, offering wide views over Vienna and the Danube valley. The complex includes several buildings, among them the Palas and other historical structures arranged across the summit.

Built probably in the 12th century as a princely castle of the Babenbergs and later the Habsburgs, it began to decay from 1377 after Albrecht III expanded Laxenburg. It was probably blown up during the First Turkish Siege of 1529. Around 1720 Karl VI had Antonio Beduzzi design a palace on the site; this burned in 1791 and was restored, serving Charles Joseph de Ligne from 1794.

The hill and church take their name from Saint Leopold, patron saint of Austria, and the church on the plateau, built in 1679 under Emperor Leopold I, is also called the Leopoldikapelle. The site is owned by Klosterneuburg Monastery, which has leased it since 1787 and keeps a servitude right for church events. The Belgian field marshal Charles Joseph de Ligne lived in the rebuilt palace from 1794 until his death in 1814.

The castle and inner courtyard with the Church on the Leopoldsberg have been open to the public since June 2018; the area belongs to Klosterneuburg Monastery. The Nasenweg, laid out by Charles Joseph de Ligne, is a marked route up the Leopoldsberg. A former excursion restaurant closed in 2007, so check current opening before setting out.

The Heimkehrer-Gedächtnismal, a memorial to Austrian prisoners of war and returnees, was erected in 1948 on the foundation of one of the castle's towers. The Belgian field marshal Charles Joseph de Ligne, who also laid out the Nasenweg path, lived in the rebuilt palace from 1794 until his death in 1814.