Annaberg is a town in the district of Lilienfeld, in the Austrian state of Lower Austria. It lies in the eastern part of Austria, within the federal province of Lower Austria, and is one of the municipalities that make up the Lilienfeld district.
The town is situated in a region of Lower Austria known for its Alpine foothills and forested landscapes, in the valley area associated with the Traisen river system. Like much of the Lilienfeld district, the surrounding area is mountainous and rural, with a character shaped by its location in the eastern Alps.
Annaberg is administratively organized as a single municipality within the district, which has its seat in the town of Lilienfeld. The community is part of the broader Mostviertel region of Lower Austria, the southwestern quarter of the province.