Dub Lemna ingen Tighearnáin, Queen of Ireland, died 943.
Dub Lemna was a daughter of Tighearnáin mac Seallachan, King of Breifne (died c. 888).
c. 893), was the eponym and ancestor of the clan Ó Ruairc, Kings of Breifne.
Her children by Donnchad are uncertain but they do not include Oengus mac Donnchada, who appears to have been a son of Cainnech ingen Canannán of Ailech, who died in 929.
The Chronicon Scotorum, sub anno 943, state that "Dub Léna daughter of Tigernán, king of Bréifne, wife of the king of Temair, i.e. Donnchad son of Flann, dies.."