Weinburg is a municipality in the district of Sankt Pölten-Land, in the Austrian state of Lower Austria. It lies in the Pielach valley, roughly 10 kilometres south of the city of Sankt Pölten, the state capital.
The settlement is best known for Weinburg Castle (Schloss Weinburg), a moated castle whose origins date to the twelfth century. The building has been rebuilt and extended several times over the centuries and is now privately owned. The surrounding area is agricultural, with vineyards and farmland on the slopes above the Pielach river.
Weinburg is connected to the regional road and rail network linking it with Sankt Pölten and the towns of the Pielach valley. Its population is a few thousand, and it functions largely as a residential community within the Sankt Pölten metropolitan area.