Oupeye Castle is a castle located in Oupeye in the Belgian province of Liège. The castle has medieval origins with a keep, a fortified residence tower, dating from the 12th or 13th century.
The first written mention of a fortified house and a feudal lord of Oupeye dates from 1176, with a mention of a Gérard d'Oupeye. In the 13th century, there was a Lambert d'Oupeye, a Liège knight known for his bravery. In the 17th century, the Curtius family, arms merchants from Liège, became its owners. Jean Curtius then had the castle renovated. In the 18th and 19th centuries, other renovations followed. The castle, after having belonged to the Curtius family, passed into the hands of the Grady de Horion family, who sold it to the town of Oupeye in 1970. Today, it is used as a cultural center. The whole is accessible by a bridge over the moat and is made up of two parts. There is a medieval keep which dates from the 12th or 13th century. The square construction with walls 1.7 m thick is made with blocks of natural stone, restored in brick and limestone in the 17th century. The keep once had 4 floors. The upper floors were demolished after 1970 when the tower threatened to collapse. On the other side of the inner courtyard is the castle consisting of two perpendicular wings, redeveloped in a neoclassical style in the 18th and 19th centuries on a much older base.