Máel Dúin mac Áedo (died 786) was a possible King of Munster from the Eóganacht Locha Léin branch of the Eóganachta.
He was the son of Áed Bennán mac Conaing (died 733), a king of Iarmuman or West Munster and great great grandson of Áed Bennán mac Crimthainn (died 618) who may have been King of all Munster.
He is next mentioned in the Annals of Innsifallen under the year 766 where he was defeated by the Uí Fidgenti and the Arad Cliach of County Limerick at the Battle of Énboth Breg.
[7] In 779 a civil war is recorded among the men of Munster which involved the affairs of Desmond (South Munster), the King of Eóganacht Raithlind, Fergal son of Éladach, was slain by Breislén of Béirre (the Bear barony of County Cork - a territory of the Corcu Loígde).
Máel Dúin is mentioned in the West Munster Synod as the last king of Iarmumu who would rull over the Ciarraige.