Mongfind (or Mongfhionn in modern Irish)—meaning "fair hair" or "white hair"—is a figure from Irish legend. She is said to have been the wife, of apparent Munster origins, of the legendary High King Eochaid Mugmedón and mother of his eldest three sons, Brión, Ailill and Fiachrae, ancestors of the historical Connachta. She was Eochaid's first wife; his second wife, Cairenn, gave birth to Niall of the Nine Hostages. Several tales depict Mongfind as an adversary of Niall. Mongfind is also said to have been the sister of Crimthann mac Fidaig, King of Munster and the next High King of Ireland, whom she is said to have killed with poison in a bid to make her son king. She drank the poisoned drink to convince Crimthann, and died soon after at Samhain.