Show ContentsMcDuffy History, Family Crest & Coats of Arms

The original Gaelic form of McDuffy was Ó Dubhthaigh. The first portion of the name is the word "dubh," which means "black," while the second portion is likely an obsolete Irish forename. 1

The sept claim descent from the ancient Heremon Kings of Ireland. Through O'Conner Faley, Lords of Offaley (now Offaly), they descend from "Cahir Mor, King of Leinster in the beginning of the second century. He divided his great possessions amongst his thirty sons in a Will called 'The will of Cahir More,' contained in the 'Book of Leacan' and in the 'Book of Balymote.' His posterity formed the principal families in Leinster." 2 O'Duffy was listed as one of these such families.

Early Origins of the McDuffy family

The surname McDuffy was first found in Connacht (Irish: Connachta, (land of the) descendants of Conn), where they held a family seat from very ancient times, and were one of the many families descended from the great Kings of Ireland called the "Three Collas." Descending from the Clan Colla was Duffy, Lord of Fermanagh.

However, "there are several distinct septs of O'Duffy. One belongs to the parish of Lower Templecrone in the diocese of Raphoe, Co. Donegal, the patron saint of which is the seventh century Saint Dubhthach, or Duffy. The Connacht sept, the centre of whose territory was Lissonnuffy or Lissduffy near Strokestown, named after them, was remarkable for the number of distinguished ecclesiastics it produced." 3

Without a doubt, the oldest records of the family include: Muireadach Ó'Dubthaigh (Murdagh O'Duffy) (1075-1150), Archbishop of Tuam in the county of Connaught and Cadhla Ó'Dubthaigh, (Cele O'Duffy) Archbishop of Tuam, Ambassador to Henry II in 1175. 3

The Monaghan branch of the family were principally found in Attyduffy or Attyduff 2 and "modern statistics show that it is now most numerous name in Co. Monaghan." 1

Early History of the McDuffy family

This web page shows only a small excerpt of our McDuffy research. Another 266 words (19 lines of text) covering the years 1075, 1150, 1175, 1501, 1527, 1615, 1671, 1675, 1809 and 1871 are included under the topic Early McDuffy History in all our PDF Extended History products and printed products wherever possible.

McDuffy Spelling Variations

The Middle Ages saw a great number of spelling variations for surnames common to the Irish landscape. One reason for these variations is the fact that surnames were not rigidly fixed by this period. The following variations for the name McDuffy were encountered in the archives: Duffey, Duff, Duffy, O'Duffey, O'Duffy, Duffe, O'Duffe, Doey, Dohey, Doohey, O'Dowey and many more.

Early Notables of the McDuffy family

Prominent amongst the family at this time was Father Eugene O'Duffy (c. 1527-1615), preacher and satirist on the apostate bishop Miler Magrath; The Most Reverend Patrick...
Another 26 words (2 lines of text) are included under the topic Early McDuffy Notables in all our PDF Extended History products and printed products wherever possible.

McDuffy Ranking

In the United States, the name McDuffy is the 11,822nd most popular surname with an estimated 2,487 people with that name. 4


United States McDuffy migration to the United States +

A great mass of Ireland's native population left the island in the 19th century, seeking relief from various forms of social, religious, and economic discrimination. This Irish exodus was primarily to North America. If the migrants survived the long ocean journey, many unfortunately would find more discrimination in the colonies of British North America and the fledgling United States of America. These newly arrived Irish were, however, wanted as a cheap source of labor for the many large agricultural and industrial projects that were essential to the development of what would become two of the wealthiest nations in the western world. Early immigration and passenger lists indicate many people bearing the McDuffy name:

McDuffy Settlers in United States in the 18th Century
  • Dudly McDuffy, who landed in New York in 1740 5

Contemporary Notables of the name McDuffy (post 1700) +

  • Izetter McDuffy, American Democratic Party politician, Delegate to Democratic National Convention from New Jersey, 1980


  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. MacLysaght, Edward, Irish Families Their Names, Arms and Origins 4th Edition. Dublin: Irish Academic, 1982. Print. (ISBN 0-7165-2364-7)
  4. "What are the 5,000 Most Common Last Names in the U.S.?". NameCensus.com, https://namecensus.com/last-names/
  5. Filby, P. William, Meyer, Mary K., Passenger and immigration lists index : a guide to published arrival records of about 500,000 passengers who came to the United States and Canada in the seventeenth, eighteenth, and nineteenth centuries. 1982-1985 Cumulated Supplements in Four Volumes Detroit, Mich. : Gale Research Co., 1985, Print (ISBN 0-8103-1795-8)


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