Áed Rón (‘seal[-like]’) (d. 735), son of Bécc Bairrche and overking of Ulaid, was a member of the Cenél Demmáin lineage of Dál Fiatach. His father Bécc Bairrche (qv), was previously king of Ulaid (east Ulster), having abdicated in 707. His mother, Coinchend daughter of Congal Cennfhota (qv) of Dál Fiatach, also bore six of Áed Rón's brothers; there were also five half-brothers. The dynastic centre in Áed's time was at Dún dá Lethglass (Downpatrick); later, the dynasty relocated to the triple-ramparted fort of Dun Echdach (Duneight). Áed's succession to the overkingship of Ulster was facilitated when the Dál nAraide dynast Cú Chuaráin, who had assumed provincial suzerainty on the abdication of Bécc Bairrche, was slain by a kinsman. To secure his position, Áed slew another Dál nAraide claimant, Lethlobar, at the battle of Mag Eilne (709). This, however, did not end the struggle for supremacy; three years later one of Áed's brothers, Dubthach, was killed by the Dál nAraide. Then in 714 Áed and his brothers again defeated their dynastic rivals.
In 735 Áed was slain by the Uí Néill high-king Áed Allán (qv) at the battle of Fochairt (Faughart, Co. Louth). An ally of Áed Rón, Conchad son of Cuanach, king of Uí Echach Cobo, was also slain. The battle reputedly came about due to the profanation of Cell Chonna by a follower of Áed Rón, this church being subordinate to Armagh. On Áed Rón's death, the provincial overkingship passed to a Dál nAraide claimant, Cathussach (d. 749), and then reverted to Áed's sons Bressal and Fiachnae (qv), from whom most of the later kings of Dál Fiatach would descend. A grandson of Áed Rón, Diarmait (qv), became an important leader of the Céli Dé reformers.