In Irish mythology Delbáeth (or Dealbhaeth) was the son of either Aengus or Ogma of the Tuatha Dé Danann, and Ethniu of the Fomorians. He succeeded his grandfather Eochaid Ollathair, aka the Dagda, as High King of Ireland. He was the father, by Ernmas, of the three eponymous Irish goddesses Ériu, Banba and Fodla. He ruled for ten years, before dying at the hand of his son, Fiachna.

He and Tuireann may be the same character, as both are credited as the father of Brian, Iuchar and Iucharba.

The Delbhna, a people of early Ireland, claimed descent from him.