Henry IX may refer to:
- Henry IX, Duke of Bavaria, also called the Black
- Henry Benedict Stuart (1725–1807), Jacobite claimant to the throne of England, Scotland and Ireland
- Henry Dundas, 1st Viscount Melville (1742–1811), nicknamed "Henry IX" for his personal power in Scotland
- In Martin Amis' Yellow Dog (novel) (2003), a Henry IX (probably Prince Henry of Wales) rules the United Kingdom
- In the referenced alternate version of Man in the High Castle within Kingsley Amis's The Alteration, Henry IX of England is the son of Henry VIII and succeeds him
- In the Code Geass reality, Henry IX is an illegitimate son of Queen Elizabeth I by one of her lovers
- Possible future regnal name for Prince Harry of Wales (born 1984), if he succeeds to the throne of the United Kingdom