William V may refer to:
- William V, Duke of Aquitaine (969–1030)
- William V of Montpellier (1075–1121)
- William V, Marquess of Montferrat (1191)
- William V, Count of Nevers (before 11751181)
- William V, Duke of Jülich (1299–1361)
- William V, Count of Holland (1330–1389)
- William V of Jülich-Berg (1516–1592)
- William V, Duke of Bavaria (1548–1626)
- William V, Landgrave of Hesse-Kassel (1602–1637)
- William V, Prince of Orange (1748–1806)
See also
- Guillaume V, lists people named with the French equivalent of William V
- Guillaume V, Grand Duke of Luxembourg (born 1981)
- King William (disambiguation)
- Prince William (disambiguation)
- William, Prince of Wales (born 1982), possible future regnal name