Fiachnae mac Ainbítha
Fiachnae mac Ainbítha or Fiachna mac Ainfítha was a Dál Fiatach king of Ulaid, which is now Ulster, Ireland. He was the son of Ainbíth mac Áedo, a previous king of Ulaid. He ruled briefly in 886.
In 883 he was responsible for the killing of his uncle Eochocán mac Áedo, leth-rí of Ulaid jointly with his other uncle, Airemón mac Áedo. Fiachnae succeeded Airemón as sole king in 886 but was promptly killed by his own associates.