Báetán (d. 586), son of Ninnid and putatively king of Tara, belonged to the Cenél Conaill dynasty. His father, Ninnid son of Duí, was an early representative of the lineage of Cenél Duach. He had at least two brothers: Eochaid, who was slain by the Cianachta, and Feradach, father of Laisrén, third abbot of Iona. He was also a second cousin of Colum Cille (qv). According to the ‘Banshenchas’ (lore of women), Báetán married Cacht, who is anachronistically described as a daughter of the king of Fine Gall; she may have belonged to a minor lineage of east Brega (the northern part of Co. Dublin). They had at least one son, Conall.
Báetán came to prominence from the later 560s, whether or not he fought with his father at the battle of Cúl Dreimne (561). A Middle Irish list includes him among the kings of Tara, although he does not feature in the Old Irish regnal poem ‘Baile Chuinn’. It is possible that he owed his position as overking to the support of his powerful cousin Áed (qv) son of Ainmere (qv), who certainly ranked among the strongest leaders of the Uí Néill and took a more active military role than Báetán himself. According to the Annals of Ulster, Báetán was killed (586) at the battle of Léim in Eich, at the instigation of Colmán – an annalistic gloss equates the latter with Colmán Bec (qv), ancestor of perhaps more than one of the Southern Uí Néill dynasties. His successor as overking was Áed son of Ainmere, who immediately avenged Báetán by killing Colmán in battle. The lineage of Cenél Duach continued through Báetán's son Conall, although it failed to supply later kings of Cenél Conaill.