Show ContentsO'Mahoom History, Family Crest & Coats of Arms

The many Irish surnames in use today have long rich histories behind them. The name O'Mahoom originally appeared in Gaelic as Ó Mathghamhna, which is derived from the word mathghamhan, which means bear. 1 The modern Gaelic spelling is Ó Mahúna.

"Hugh Gharbh (or Hugh the Terrible), a younger brother of Laeghaire who is No. 93 on the 'O'Donaghue' (of Lough Lein) pedigree, was the ancestor of O'Mathamhna; anglicized O'Mahony and Mahony." 2

Early Origins of the O'Mahoom family

The surname O'Mahoom was first found in County Cork (Irish: Corcaigh) the ancient Kingdom of Deis Muin (Desmond), located on the southwest coast of Ireland in the province of Munster, where they held a family seat from ancient times.

"The O'Mahonys were anciently located in Cork and Kerry, where they were powerful Chiefs and sometimes styled Princes. They had several castles along the sea-coast. In County Cork an O'Mahony was Lord of Ivaugh, in the Barony of West Carbery, and an O'Mahony was Chief in Kinalea Barony. In County Kerry there was a Chief of the name in the Barony of Iveragh, and there were O'Mahonys in the Barony of Clanmaurice. The majority of persons of the name of Mahony or O'Mahony are still found in these two counties." 3

The Book of Munster clearly states: "The O'Mahony family were 'undisputed kings of Raithlean, and had a right to be kings of Cashel whenever that kingdom happened to be vacant; and from whom the Kings of Cashel had no right to demand anything except a bowing of the head.' " 2

Early History of the O'Mahoom family

This web page shows only a small excerpt of our O'Mahoom research. Another 179 words (13 lines of text) covering the years 1014, 1639, 1679 and 1987 are included under the topic Early O'Mahoom History in all our PDF Extended History products and printed products wherever possible.

O'Mahoom Spelling Variations

Official documents, crafted by early scribes and church officials, primarily contained names that were spelled according to their pronunciation. This lead to the problem of one name being recorded under several different variations, creating an illusion that a single person was many people. Among the many spelling variations of the surname O'Mahoom that are preserved in the archival documents of the time are Mahoney, O'Mahoney, O'Mahony, Mahony and others.

Early Notables of the O'Mahoom family

Another 47 words (3 lines of text) are included under the topic Early O'Mahoom Notables in all our PDF Extended History products and printed products wherever possible.

Migration of the O'Mahoom family

In the 18th and 19th centuries hundreds of thousands of Irish people immigrated to North American shores. The early settlers were enticed by the promise of their own land, but they were moderately well off in Ireland when they decided to emigrate. Therefore, they were merely carrying out a long and carefully thought out decision. The 1840s saw the emergence of a very different trend: thousands of extremely desperate people crammed into passenger boats hoping to find any type of opportunity. The Irish of this decade had seen their homeland severely stricken by crop failures which resulted in widespread disease and starvation. At whatever time the Irish immigrants came to North America, they were instrumental in the rapid development of the emerging nations of the United States and what would become known as Canada. An exhaustive search of passenger and immigration lists has revealed many persons bearing the name O'Mahoom, or one of its variants: Cornelius, Daniel, Denis, James, Jeremiah, John, Mary, Michael, Patrick, Peggy, Thomas, Timothy and William Mahoney, who all arrived in Philadelphia, Pennsylvania between 1840 and 1860.



  1. MacLysaght, Edward, The Surnames of Ireland. Ireland: Irish Academic Press, sixth edition, 1985. Print. (ISBN 0-7165-2366-3)
  2. O'Hart, John, Irish Pedigrees 5th Edition in 2 Volumes. Baltimore: Genealogical Publishing Company, 1976. Print. (ISBN 0-8063-0737-4)
  3. Matheson, Robert E., Special Report on Surnames in Ireland with Notes as to Numeric Strength, Derivation, Ethnology, and Distribution. Dublin: Alexander Thom & Co., 1894. Print


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