Nuadu, in Celtic mythology, king of the Tuatha Dé Danann, who lost his hand in the battle of Mag Tuired and with it his right to govern. Dian Cécht replaced the hand with a hand made of silver; he later received a functional human hand from Dian Cécht’s son Miach and was thereupon able to overthrow his successor, Bres. From inscriptional evidence it is clear that Nuadu was originally a god.