Denethor can refer to three characters:
- Denethor, son of Lenwë and leader of the Laiquendi who was killed in the First Battle of Beleriand.
- Denethor I (T.A. 2375 - 2477), tenth Ruling Steward of Gondor.
- Denethor II (T.A. 2930- 3019), twenty-sixth Ruling Steward of Gondor during the War of the Ring, and father of Boromir and Faramir.