McCarthy/MacCarthy is one of the most common surnames in Ireland today and is prevalent throughout Counties Cork and Kerry. Through migration over the past four hundred years, McCarthys now reside in many countries throughout the world.

In October 2002, the McCarthy Surname Study was started through Family Tree DNA, Inc. (FTDNA) of Houston, Texas, U.S.A. The McCarthy Surname Project will attempt through Y-DNA analysis to compare individuals with surnames common to the McCarthy Clan and to identify any genetic markers which might single out groups of McCarthys or their immediate predecessors. These surnames include but are not limited to the following: McCarthy, MacCarthy, Macarthy, McCarty, and McCarter.

Apart from facilitating family connections among McCarthys throughout the world, it is hoped to identify the yDNA profiles associated with both the leading families of the various MacCarthy septs (Mór, Reagh, of Muskerry, of Duhallow, Glas etc.) identifiable in the ancient histories as in use from ca. 14th century and more recent agnomens adopted to distinguish one McCarthy family grouping from another e.g. Cnoic, Crimeen, Cruig, Daunt, Farshing (Fairsinn), Guidagh (Gaibhdeach), Meenig (Muineagh), Norsa, Rabagh, Sowney, McAuliffes and O'Crimeens (or variants of these) are also welcome to join the project if they can trace Munster origins, since these surnames are claimed to have origins in branches of the McCarthy family.

As more data becomes available, the findings of this and other projects for surnames which the ancient histories and genealogies indicate derive from first millenium A.D. Eóghanacht origins can be compared with the content of these texts.

Jeremiah McCarthy
(May 1827 - 7 Apr 1908)
James Henry McCarthy
(15 Jul 1866 - 13 Feb 1932)
George Jeremiah McCarthy
(20 Aug 1890 - 30 Jan 1952)
James Henry McCarthy
(30 Jul 1915 - 27 Aug 1953)
James George McCarthy
(26 May 1938 - 12 Nov 1994)
338137
Haplogroup: R-M269
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