The Horndon mint was an Anglo-Saxon mint established at Horndon-on-the-Hill in Thurrock, Essex. It is known from a single coin of the reign of Edward the Confessor. The only surviving example of a coin from the Horndon mint was among the hoard of coins found in the 18th century in a basement near St Mary Hill church, in the ward of Billingsgate, London, England. The coin is described as being of the sovereign/martlet type, with the head of the sovereign and a martlet mint mark; it was minted between 1056 and 1059. It bears the inscription Dudinc on Hornidune on the reverse. Hornidune is the earliest recorded form of Horndon, which appears in Domesday as Horniduna.