Is it possible that the famous poet Eochaid ua Flainn — known to be author of some of the poetry preserved in Lebor Gabála Érenn — is one and the same person as the airchinneach (erenagh) of Armagh, Eochaid ua Flannucáin (†1004), to whom some stray quatrains are attributed in the Annals of Ulster? Eochaid ua Flannucáin is described as a senchaid in his death notice, a man widely respected by other poets and whose books are in demand. Furthermore, he belonged to the most famous learned family in Armagh in his time: Clann Sínaich. As for Eochaid ua Flainn, there is a little evidence in his poems which connects him with the Armagh district and with Clann Eachach, the population-group to which Clann Sínaich belonged. The surnames ‘Ó Flainn’ and ‘Ó hEachaidh’ are attested locally (and there is historical evidence for the latter as tenants of the church). Evidence for the patrimony of Muintir Eachaidh and Muintir Fhlainn is preserved in the local place-names Baile Uí Eachaidh (Ballyaghy) and C(o)ill Uí Fhlainn (Killylyn); this is significant in that there are place-names elsewhere in the locality which preserve the names of learned families and church officials who were connected to learning. Eochaid ua Flannucáin had a son, Máel Muire (†1020), who served as abbot of Armagh and led the funeral ceremonials for the high-king, Brian Boru, when he was buried in Armagh in 1014. Máel Muire is mentioned in the text known as Comarbada Pátraic (the ‘successors of Patrick’), the oldest copy of which is preserved in the Book of Leinster. Máel Muire mac Eochacáin is the name given to him in that document. If variation between the forms Eochaid and Eochacán is permissible in the case of his father’s name, it is possible that similar variation existed in the case of the name of his great-grandfather, i.e. Flann ~ Flannucán. On the basis of the totality of the evidence, it is argued that Eochaid ua Flannucáin and Eochaid ua Flainn are varying names for the same person.