In Irish mythology, Cethlenn (Old Irish), Cethleann (Modern Irish, or Cethlenn of the Crooked Teeth) was the wife of Balor of the Fomorians and, by him, the mother of Ethniu. She was also a prophetess and warned Balor of his impending defeat by the Tuatha Dé Danann in the second battle of Magh Tuiredh. During that battle she wounded the Dagda.
- Monaghan, Patricia (2009). The Encyclopedia of Celtic Mythology and Folklore. Infobase Publishing. p. 86. ISBN 1438110375.
- Joyce, Patrick Weston (1901). The Origin and History of Irish Names of Places, Volume 1. Longmans, Green. p. 163. ISBN 1143292944.