Clearchus (Greek: Kλέαρχoς, Klearkhos) was a son of Dionysius, tyrant of Heraclea and of Amastris, the daughter of the brother
of Darius III Codomannus, Oxyathres. He succeeded, together with his brother also named Oxyathres, to the sovereignty of Heraclea
on the death of Dionysius, 306 BC