O'Doy History, Family Crest & Coats of Arms
- Origins Available:
The original Gaelic form of O'Doy was O Dubhthaigh. The first portion of the name is the word "dubh," which means "black," while the second portion is likely an obsolete Irish forename. 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."  O'Duffy was listed as one of these such families.
Early Origins of the O'Doy family
The surname O'Doy 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." 
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. 
The Monaghan branch of the family were principally found in Attyduffy or Attyduff  and "modern statistics show that it is now most numerous name in Co. Monaghan." 
Important Dates for the O'Doy family
This web page shows only a small excerpt of our O'Doy research. Another 266 words (19 lines of text) covering the years 1075, 1150, 1501, 1175, 1527, 1615, 1527, 1615, 1675, 1671, 1809 and 1871 are included under the topic Early O'Doy History in all our PDF Extended History products and printed products wherever possible.
O'Doy Spelling Variations
Before widespread literacy came to Ireland, a name was often recorded under several different variations during the life of its bearer. Accordingly, numerous spelling variations were revealed in the search for the origin of the name O'Doy family name. Variations found include Duffey, Duff, Duffy, O'Duffey, O'Duffy, Duffe, O'Duffe, Doey, Dohey, Doohey, O'Dowey and many more.
Early Notables of the O'Doy family (pre 1700)
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 O'Doy Notables in all our PDF Extended History products and printed products wherever possible.
Migration of the O'Doy family
Thousands of Irish families left for North American shores in the 19th century. These people were searching for a life unencumbered with poverty, hunger, and racial discrimination. Many arrived to eventually find such conditions, but many others simply did not arrive: victims of the diseased, overcrowded ships in which they traveled to the New World. Those who lived to see North American shores were instrumental in the development of the growing nations of Canada and the United States. A thorough examination of passenger and immigration lists has disclosed evidence of many early immigrants of the name O'Doy: Alice Duffey who landed in Maryland in 1724. In Newfoundland, Philip Duffy settled in Harbour Grace in 1827; Thomas Duffey settled in St. John's in 1829.
- ^ O'Hart, John, Irish Pedigrees 5th Edition in 2 Volumes. Baltimore: Genealogical Publishing Company, 1976. Print. (ISBN 0-8063-0737-4)
- ^ MacLysaght, Edward, Irish Families Their Names, Arms and Origins 4th Edition. Dublin: Irish Academic, 1982. Print. (ISBN 0-7165-2364-7)
- ^ MacLysaght, Edward, The Surnames of Ireland. Ireland: Irish Academic Press, sixth edition, 1985. Print. (ISBN 0-7165-2366-3)