Château de Deulin is an 18th-century castle located in the village of Deulin within Hotton municipality in Luxembourg Province, Wallonia, Belgium. Built between 1758 and 1770 by Guillaume-Joseph de Harlez and his descendants, the castle features a distinctive U-shaped design constructed of whitewashed brick and blue stone under slate roofing, with an inner courtyard surrounded by outbuildings. The seigniorial chapel, dedicated to Saint Remacle, displays baroque architectural elements and is decorated with elaborate rococo stuccowork by artist François-Joseph Dukers, complemented by paintings by Jean-Dieudonne Deneux. The grounds include an 18th-century walled garden redesigned in the French garden style, with landscaped heritage trees offering views of the Ourthe River. The castle remains inhabited by the de Harlez de Deulin family and hosts special events including Christmas markets and antique fairs.