Katzelsdorf is a municipality in the district of Wiener Neustadt-Land, in the Austrian state of Lower Austria. It lies in the eastern part of the country, in the industrial quarter south of Vienna.
The town is situated at the foot of the Rosalia Mountains and on the river Leitha, about 5 kilometres southeast of the city of Wiener Neustadt. Its position on the Leitha places it near the historic border between Lower Austria and the neighbouring province of Burgenland.
Katzelsdorf's setting between the Rosalia range and the Leitha gives it a landscape of low wooded hills and river plain, within easy reach of Wiener Neustadt, the main urban centre of the surrounding district.