Val-Saint-Lambert Abbey (French: Abbaye du Val-Saint-Lambert) was a Cistercian abbey in the Prince-Bishopric of Liège. It is situated in Seraing on the right bank of the Meuse, within the Walloon municipality of Belgium, about 13 kilometres (8.1 mi) southwest of Liege. Founded in 1202, the abbey's monks were expelled during the French Revolution. In the 19th century, the building ruins were converted into the Val Saint Lambert crystal factory. The structure is considered to be an important example of Cistercian architecture.
Up to the year 1192, the site was almost deserted. The foundation of the abbey is attributed to Hugues de Pierrepont, Bishop of Liège, who in 1187 decided to establish Val-Saint-Lambert. Construction began in 1202 after he gave a tract of land and woods situated in what was then called the Champ des Maures to a group of monks. The abbey was a daughter house of Signy Abbey in Ardennes, France, which was a daughter house of Igny Abbey. Val-Saint-Lambert Abbey was inhabited by a religious community for centuries; it prospered and became powerful. The abbey's chateau served as the summer palace of the Prince-Bishopric of Liège. The abbot Simon de Harlez, Val-Saint-Lambert's sponsor, canon of St. Lambert's Cathedral, Liège, and adviser to the Prince-Bishop, began an expansion project in 1750, funded by his coal earnings. It was completed before 1796 when the monks were expelled as a result of the French Revolution at which time the buildings were demolished and the holdings were sold as public goods. In 1825, the abbey ruins were purchased by the chemist François Kemlin and the engineer Auguste Lelièvre, who converted the building into a glass works. Since 1826, it has been used by the crystal manufacturer, Val-Saint-Lambert. In 1846, Val Saint-Lambert merged with the Societe Anonyme des Manufactures de Glaces.