William III of England (1650-1702), also William III of Orange.

Sir William Douglas the Hardy (died c. 1298).

William III of the Netherlands (1817–1890).

William I, Duke of Bavaria (1330–1389), also William III of Hainaut.

William III of Toulouse (died 1037).

William III of Sicily (1190–1198).

William III of Aquitaine (915–963).

William III of Montferrat (970–1042).

Uilleam III, Earl of Ross (died 1370).

William I, Count of Hainaut (1286–1337), also William III of Holland.

William III of Ponthieu (c. 1095–1172).

William III of Cagliari (ruled 1256–1258).

William III of Dampierre (1224–1251).

William III, Duke of Bavaria (1375–1435).

William III, Duke of Luxembourg (1425–1482).

William III of Provence (died after 1037).

William III of Angoulême (1084–1118).