Ua Conchobair, Conchobar (d. 1144), a son of Tairdelbach, king of Dublin and of Mide, belonged to the Síl Muiredaig dynasty of Connacht. His father Tairdelbach Ua Conchobair (qv) (d. 1156) was claimant to the high-kingship of Ireland; his mother is not recorded. He had at least a dozen brothers or half-brothers from his father's several marriages and liaisons. Amongst these were Áed, Cathal Migarán (slain 1152), Domnall Midech (d. 1176), Brian Luignech (d. 1181), Muirchertach (d. 1210), and Máel-Ísu, abbot of Roscommon (d. 1223); the most distinguished of his siblings were Ruaidrí (qv) (d. 1198) and Cathal Crobderg Ua Conchobair (qv), who achieved high-kingship of Ireland and overkingship of Connacht respectively.
In 1126, when he was probably no more than 18 years of age, Conchobar was appointed king of Dublin by his father. A year later, however, he faced a revolt of the Leinstermen, who expelled him and forced his father to recognise Domnall grandson of Fáelán as their king, thereby forfeiting the lives of their hostages. Despite this setback, Conchobar continued to take a leading role in dynastic affairs. In 1135 he led his father's forces into the sub-kingdom of Uí Maine to enforce obedience. The following year he blinded his brother Áed – an episode perhaps connected with a revolt within the family for which another sibling, Ruaidrí, was imprisoned. Conchobar was rewarded for his loyalty to his father, being appointed to the kingship of Mide in 1143, when Tairdelbach deposed Murchad Ua Máelshechlainn (qv) from that dignity.
Six months later Conchobar was murdered at Belach Mune na Sirride (probably a roadway near Mullingar, Co. Westmeath) by a party of Mide nobles led by Ua Dublaích, local ruler of Fir Tulach (barony of Fartullagh). In response, his father invaded Mide, devastating and partitioning the province. Later kings of the Irish of Connacht descended, for the most part, from Conchobar's half-brother Cathal Crobderg.