Wallhausen is a municipality in the Mansfeld-Südharz district of Saxony-Anhalt, Germany. It is located on the Helme river north of the Kyffhäuser mountain range and the border with Thuringia. Wallhausen is part of the Verbandsgemeinde ("collective municipality") Goldene Aue. The municipality consists of the 4 villages Wallhausen, Hohlstedt, Martinsrieth and Riethnordhausen.
In 909 Henry the Fowler, the son of Duke Otto I of Saxony, married Matilda at the Pfalz of Wallhausen, their son Otto was possibly born here in 912. King Otto III gave the castle to his aunt Abbess Matilda of Quedlinburg in 985. Wallhausen later was a possession of the Saxon Electorate, it became part of the Prussian Province of Saxony in 1815.