In Ulster, it was the name of a family based in the parish of Ardara, in Co. Donegal, who were hereditary holders of the church lands of Shanaghan. The eponymous ancestor was Monach, son of Ailloll Mor. Other variant anglicisations in this area include Moany and Money.
The Connacht family were located in the parish of Easky in the barony of Tireragh in Co. Sligo, where "Meeny" is often the English version used. In Munster, reflecting the different pronunciation, the English is often "Mainey". But the most notable family arose in Leinster, in the modern Co. Offaly, where they were concentrated around the parish of Lemanaghan. They were hereditary guardians of the shrine of St. Monaghan. Their descendants are by far the mist numerous today, although the name has now spread throughout Ireland.
The Sligo family gave their name to the townland of Ballymeeny in Esky parish. The Offaly family are very well represented, with Ballymooneys in Offaly, Laois and Wicklow, as well as Mooneysland, also in Offaly, and 2 Mooneystowns and a Knockmooney in Meath.
In Munster, where the name is relatively uncommon, O Maonaigh was generally anglicised as "Mainey", more accurately reflecting the southern pronunciation of the name.
The later-to-become-infamous Tammany Hall was founded in New York City in 1789 by William Mooney, a former soldier and a prominent anti-Federalist.
Donagh Mooney, an Irish Franciscan, was guardian of the young O?Neill, Earl of Tyrone and O?Donnell, Earl of Tirconnell at Louvain in 1626.
Ria Mooney (1904-1973) joined the Abbey in 1924 and played the lead in the first production of The Plough and the Stars. She went on to produce and direct in New York and, back in Dublin from the 1940s, in the Gate, the Abbey and the Gaiety.