Ilsenburg House (German: Schloss Ilsenburg) stands in the town of Ilsenburg (Harz) in the German state of Saxony-Anhalt and was given its present appearance in the 2nd half of the 19th century. The structure was built from 1860 onwards on the west and north sides of the Romanesque monastery of Ilsenburg Abbey. The stately home, designed in the Neo-Romanesque style, was the seat of the princes of Stolberg-Wernigerode until 1945. Since 2005, it has been owned by the Ilsenburg Abbey Foundation.
In the future it is intended to make use of the house, together with the surviving, medieval cloisters (Klausurgebäude) of the monastery, as an art and cultural centre with overnight accommodation as well as a restaurant open to the public.