William of the United Kingdom

William of the United Kingdom most commonly refers to:


 * William IV of the United Kingdom (1765–1837; (r. 1830 – 1837)), known as Prince William, Duke of Clarence and St Andrews prior to ascension
 * William, Prince of Wales (born 1982), current heir apparent to British throne as eldest son of Charles III, also known as Duke of Rothesay in Scotland

William of the United Kingdom or William of Great Britain may also refer to:


 * Prince William, Duke of Cumberland (1721–1765), third and youngest son of George II
 * Prince William Henry, Duke of Gloucester and Edinburgh (1743–1805), grandson of George II and brother of George III
 * Prince William Frederick, Duke of Gloucester and Edinburgh (1776–1834), son-in-law of George III
 * Prince William of Gloucester (1941–1972), grandson of George V