William the Younger
William the Younger may refer to:
- William Peverel the Younger, son of William Peverel
- William of Jülich, known as the Younger
- William IV, Duke of Brunswick-Lüneburg, called William the Younger
- William the Younger, Duke of Brunswick-Lüneburg
- William Alexander (the younger), founder of the Scottish colony at Port-Royal
- William Cawley (younger), English lawyer and politician
- William Faithorne the Younger, English mezzotint engraver
- William Morgan (of Tredegar, younger), Welsh politician
- William Pitt the Younger, British statesman
- William Heberden the Younger, British physician
- William Godwin the Younger, English reporter and author
- William Holl the Younger, English portrait and figure engraver
- William Urwick the younger, Anglo-Irish nonconformist minister and antiquarian chronicler