Heaney is a surname of Irish origin. It is an Anglicisation of the Gaelic Ó hEignigh, thought to be based on the Gaelic Eochaidh a personal name meaning "horseman". It was mistakenly thought to derive from Éan, Gaelic for Bird. Versions of it are written in the Annals from the 8th century and has a diverse array of modern derivations and origins. They were chiefs of Fermanagh and Kings of Airgíalla before the expansion south of Uí Néill branches Cenél Fearadhaigh and Cenél nEoghain into Airgíalla and the rise of The Maguires in Fermanagh. They became allies to repel the Normans in the 13th century. Notable people with the surname include: