In Irish mythology, Naisi, Noíse or Noisiu was the nephew of King Conchobar mac Nessa of Ulster, and a son of Uisneach. He is mentioned in the tale known as the Tragic Tale of the Sons of Uisnech, or Exiles of the Sons of Uisnech, usually found within the set of stories in the Táin Bó Cúailnge, part of the Ulster Cycle.

Deirdre is a tragic heroine in the Ulster Cycle of Irish mythology. She is also known by the epithet "Deirdre of the Sorrows".