Mielmont Castle, locally known as Château de Mielmont, lies north of the village of Onoz, in the province of Namur in the Wallonia region in Belgium.
Mielmont Castle was first mentioned in 1125 as the property of Renier de Merlemont. The seignory of Mielmont was part of the County of Namur and was an important fortress that protected its border with the Duchy of Brabant, together with nearby Falnuée Castle and Villeret Tower. Until the mid-14th century it remained in the hands of the Merlemont family then it passed to the Dave (or Davre) family.
The castle lost its strategical importance after Philip the Good, Duke of Burgundy had bought the County of Namur in 1429 and inherited the Duchy of Brabant a year later. From then on the castle gradually developed into a more comfortable residence.
In the 17th century it went to the Sainte Aldegonde family. Followed by, first, the Roose family, Barons of Leeuw, and, secondly, the Coloma family who kept it until 1831 when it passed to the Beaufort family.
Mielmont Castle was built on a rocky outcrop above the valley of the river Orneau.
At present Mielmont Castle is a private residence and can thus not be visited. Only its backside can be seen from the public road down in the valley. Too bad, it looks great.