Show ContentsDemsey History, Family Crest & Coats of Arms

Today's Irish surnames are underpinned by a multitude of rich histories. The name Demsey originally appeared in Gaelic as Ó Diomasaigh, from the word "diomasach," which means "proud." 1

Early Origins of the Demsey family

The surname Demsey was first found in King's County and Queen's County, where they were traditional Chiefs of Clanmaliere, a territory that lay on both sides of the river Barrow. It contained parts of Geashill and Phillipstown in Kings County and parts of Portnehinch in Queen's County. They claim descent through the O'Connors of Offaly, specifically the 2nd century Irish King, Cathair Mor. 2

According to O'Hart, they claim descent from through the "Connor" Faley pedigree.

Early History of the Demsey family

This web page shows only a small excerpt of our Demsey research. Another 286 words (20 lines of text) covering the years 1172, 1193, 1599, 1631, 1641, 1652 and 1865 are included under the topic Early Demsey History in all our PDF Extended History products and printed products wherever possible.

Demsey 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 Demsey family name. Variations found include Dempsey, O'Dempsey, Dempsy, Dempsay, Dempsie and many more.

Early Notables of the Demsey family

Notable among the family name at this time was Sir Terence O'Dempsey, knighted May 1599, by Robert Devereux, earl of Essex, Lord Lieutenant of Ireland. Terence was created "Baron of Philipstown," and Viscount Clanmaliere, by patent dated 8th July, 1631, temp. Charles I. He had five sons, two of which were clergy:...
Another 52 words (4 lines of text) are included under the topic Early Demsey Notables in all our PDF Extended History products and printed products wherever possible.


United States Demsey migration to the United States +

To escape the religious and political discrimination they experienced primarily at the hands of the English, thousands of Irish left their homeland in the 19th century. These migrants typically settled in communities throughout the East Coast of North America, but also joined the wagon trains moving out to the Midwest. Ironically, when the American War of Independence began, many Irish settlers took the side of England, and at the war's conclusion moved north to Canada. These United Empire Loyalists, were granted land along the St. Lawrence River and the Niagara Peninsula. Other Irish immigrants settled in Newfoundland, the Ottawa Valley, New Brunswick and Nova Scotia. The greatest influx of Irish immigrants, however, came to North America during the Great Potato Famine of the late 1840s. Thousands left Ireland at this time for North America and Australia. Many of those numbers, however, did not live through the long sea passage. These Irish settlers to North America were immediately put to work building railroads, coal mines, bridges, and canals. Irish settlers made an inestimable contribution to the building of the New World. Early North American immigration records have revealed a number of people bearing the Irish name Demsey or a variant listed above, including:

Demsey Settlers in United States in the 17th Century
  • Ann Demsey, who landed in Maryland in 1679 3
Demsey Settlers in United States in the 18th Century
  • Eliza Demsey, who arrived in Virginia in 1701 3
  • Eliz Demsey, who landed in Virginia in 1704 3
  • Elizabeth Demsey, who arrived in Virginia in 1713 3
  • Eleanore Demsey, who arrived in Virginia in 1714 3
  • John Demsey, who landed in Virginia in 1717 3
  • ... (More are available in all our PDF Extended History products and printed products wherever possible.)
Demsey Settlers in United States in the 19th Century
  • Thomas Demsey, aged 26, who landed in South Carolina in 1812 3
  • Thomas Demsey, who arrived in Charleston, South Carolina in 1813 3


  1. MacLysaght, Edward, Irish Families Their Names, Arms and Origins 4th Edition. Dublin: Irish Academic, 1982. Print. (ISBN 0-7165-2364-7)
  2. O'Hart, John, Irish Pedigrees 5th Edition in 2 Volumes. Baltimore: Genealogical Publishing Company, 1976. Print. (ISBN 0-8063-0737-4)
  3. 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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