Judenburg is a historic town and municipality in Styria, Austria. It is located in Upper Styria in the Murtal region, on the Mur river and near the Aichfeld basin. The town is the administrative centre of the Murtal District, which was formed on 1 January 2012 through the merger of the former Judenburg District and Knittelfeld District. Until 31 December 2011, Judenburg was the capital of Judenburg District.