Waldhausen is a municipality in the district of Zwettl, in the Austrian state of Lower Austria. It is one of the small rural communities that make up the Zwettl district in the Waldviertel, the northwestern quarter of Lower Austria.
Like other municipalities in the district, it is a scattered settlement rather than a single large town, and it lies in a landscape of rolling hills, farmland and woodland typical of the Waldviertel region. The district seat, the town of Zwettl, serves as the administrative centre for the area.
Waldhausen is a separate place from other localities of the same name in Austria and Germany, and should not be confused with them. Its administration is organised at the municipal level within Lower Austria's district system.