Three Castles was a medieval lordship in Monmouthshire, Wales, comprising the fortifications of Grosmont, Skenfrith and White Castle.
Three Castles or Threecastles may also refer to: Three Castles of Bellinzona, Ticino, Switzerland (namely Castelgrande, Montebello and Sasso Corbaro) Three castles of Husseren-les-Châteaux or Eguisheim, Haut-Rhin, Vosges, France (namely the Dagsburg, the Wahlenburg and Weckmund Castle) Three castles at Dahn, Rhineland-Palatinate, Germany (namely Altdahn, Grafendahn, Tanstein) Threecastles Castle, Blessington, County Wicklow, Ireland. Threecastles, County Kilkenny, village in Ireland Three Castles Walk (disambiguation), various long-distance footpaths in Britain
See also Castle Three, British cycle car made 1919–1922