Many Irish clans now have yDNA surname projects. These are based on the inheritance of the yDNA chromosome down through the paternal line. This kind of project is ideally suited to families bearing Irish patronymic surnames as the yDNA results generally reflect the surname.

The goals of Irish yDNA surname projects usually include the primary one of finding of relatives in Ireland. The goals sometimes include the desire to verify paternal ancestry and the identification of place of origin of the family. A history of the clan and its various branches can also be part of the goals of Irish Surname projects.

It has been the case for years that “Irish” yDNA Surname Projects have attracted people from many countries but they held little interest for the Irish who were still resident in Ireland. The argument has been that Irish who live in Ireland “know where they come from” and don’t need to do DNA tests.

However, Irish yDNA Surname Projects really need Irish-based participants to get involved in yDNA testing, for several reasons:

Irish-based families may wish to connect with relatives, who may have emigrated in times past, where there is no paper trail or living memory to help with making these connections. How many people in Ireland can say “most of my family emigrated in the Famine and we have no idea where they went or who their descendants are”. Or “we have no contact with branches of our family who left Ireland a long time ago”. Must this be the case? DNA can open doors for the Irish who have lost track of relatives.

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Clan Gathering 3 (1)


Also, if more Irish men were involved in yDNA Surname Projects it would help the Irish diaspora who need yDNA results of Irish-based participants, to serve as “benchmarks” in their genealogical research. It is an exciting way to bridge the gap between the sometimes sad lonely emigration of the past and the modern world of global communications.

There are many commercial DNA companies which do yDNA testing. Those clans which are members of the Clans of Ireland, and have DNA projects going on, are listed below. If you click on a surname project link it will take you to the information about that particular project and give details of what is involved.

We encourage interested Irish clan members to look for their own surname DNA Project but if none exists for their surname, note that the Ireland yDNA Project caters for all Irish surnames. The Ireland yDNA Project website is at:

Please note that the science of DNA is still evolving and that membership of an Irish Clan is based on one’s inherited and chosen identity and not on bloodline descent alone.

You can read more about Irish Surnames and Genetic Testing: a Developing Science here

The following registered Irish Clans have DNA projects in progress:

                                                               The following registered Irish Clans have DNA projects in progress:

(O’) Boylan Clan
Project Administrator: Email peter@boylan.de
DNA Webpage

O’Brien Clan
Project Administrator: Mr. Dennis O’Brien Email: dennis@obrien.org.au
DNA webpage:

O’Byrne Clan
Project administrators: Mr. Paul Burns1 and Mr. Nicholas Burns2
DNA webpage

McCabe Clan
Project administrator: Dr. James M. Freed
DNA webpage see Register of Clans

Cassidy Clan
Project administrator: Mr. Glen Perdue
DNA webpage: see Register of Clans

MacCostello MacOisdealbh Clan
Project administrator: Martin Costello
Email: costellosurnameproject@gmail.com
Costello Surname Project on Facebook
Crowley Clan
Project Administrator Catherine Crowley Budd.
Email and DNA Webpage: see Register of Clans

Curtin Clan
Project administrator: Mr. Dan Curtin, 45 Bishop Nelson Road, Valatie, NY US 12184, phone 518-758-9480. Website: www.curtin.org
Email:  curtinclan@gmail.com

Dalton Clan
Project administrator: Michael Dalton
Email/DNA webpage: See Register of Clans

O’Dea Clan
Project administrator: Mr. Shane O’Dea, 45 Carysfort Park, Blackrock, Co. Dublin, Ireland Mobile 087-7789034
Website/Email: See Register of Clans

O’Donnell Clan
Project administrator: Mr. Vincent O’Donnell: Email: See Register of Clans

O’Donoghue Society
Project Administrator: Ms Elizabeth O’Donoghue
Email: elizabethod@eircom.net
DNA Webpage:see Register of Clans

O’Driscoll Clan
Project Administrator: Susan Barretta, FCGS
Contact Email:  driscolldna@pobox.com
DNA Webpage: http://driscoll.dnagen.org 
O’Driscoll DNA Project Group: http://www.familytreedna.com/groups/driscoll

Egan Clan
Project Administrator: Sue Egan
Email: spe@optusnet.com.au 
Webpage:  www.familytreedna.com/public/ClanEgan/default.aspx

Fitzpatrick Clan  
Project administrators: Dr Mike Fitzpatrick and Ian Fitzpatrick
Webpage: https://www.familytreedna.com/groups/fitzpatrick/about

Flanagan Clan
Webpage: https://www.familytreedna.com/groups/flanagan-2/about/results

Flood Clan
Project administrator: Mr. Kevin Flood Email: kpflood@clanflood.org
Webpage: http://www.clanflood.org/DNA.htm

Hosey/Hussey Clan
Project administrator: Mr. Robert b. Hosey
Email  DNA Webpage: See Register of Clans

MacGeoghegan Clan
Project administrator: Mr. James Geoghegan 
Email: See Register of Clans

McGrath Clan

McGrath Clan DNA Project
Contact Administrators: Daniel McGrath or Tim McCraw


O’Gara Clan
Project administrator: Mr. Joe O’Gara
Website: See Register of Clans

O’Haran Clan
DNA webpage: See Register of Clans

O’Higgins Clan
Project administrator: Dr. James O’Higgins Norman
Webpage: http://www.ohigginsclan.com/dnaproject.htm

O’Kane Clan
Project administrator: John A O’Kane
Email: See Register of Clans

Kavanagh Clan
Project administrator: Email:See Register of Clans

Kyle Clan
Project Administrator: Ms Pam Rooney Email: See Register of Clans.

Larkin Clan – Muinter Lorcán
Project administrator: Brad Larkin
Email:  DNA webpage: See Register of Clans

McGillycuddy of the Reeks
Project administrator: Dr. Brian McEvoy, Trinity College, Dublin.

MacMahon Clan
Project administrator: Michael Mitchell Email: clanmacmahon@gmail.com

O’Mahony Clan
Project administrator : Dr. Finbar O Mahony,
DNA webpage Email: fin.omahony@gmail.com

O’Malley Clan
Project administrator: Dr Maurice Gleeson
email: mauricegleeson@doctors.org.uk
DNA webpage: https://www.familytreedna.com/groups/omalley/activity-feed 

Mannion Clan Surname Project
Project administrator: Jim Hollarn
Email: hollarnj@cs.com
Webpage: https://www.familytreedna.com/groups/mannion-surname/about/background

Mannion by DNA Network
Project administrator: Martin Curley
Email: martinjcurley@gmail.com
Facebook: https://www.facebook.com/groups/259339384445890/

(O’) Molloy Clan
Project Administrators:  Thomas Molloy and John P. Malloy
Webpage: http://www.omolloy.com/genealogy/dna-genealogy

McMullen Clan
Project administrator: Lt. Col. Lyn McMullen
DNA webpage: www.familytreedna.com/public/mullen/

Mulvihill Clan
Project administrators: Mr. James M. Mulvihill: Email:jmulvihill@comcast.net
Mr. Aiden Mulvihill Email: aidenmulvihill@gmail.com

O’Neill Clan
Project administrator: Sean O’Neill
DNA webpage: See Register of Clans

Nelligan Clan
Project administrator: Megan Smolenyak Smolenyak, Ancestry.com
Email: smolenyak@att.net

Nolan Clan DNA 
Project administrator: Zak Jones .
Webpage:  https://www.familytreedna.com/groups/nolan 
Email: ftdna.nolan@gmail.com
Facebook: https://www.facebook.com/groups/NolanSurnameFTDNA/

Roche Clan
Project Administrator: Dr. Peter Roche
Webpage: http://www.familytreedna.com/public/Roache/

O’Shaughnessy Clan
Project adminstrator: Desmond O’Shaughnessy
Email: dkos@btinternet.com

O’Shea Clan – Ó Séaghdha
Project Administrator:  Mrs Margaret Jordan Email:  m.jordan246@gmail.com

O’Sullivan Clan
Project administrator: Shanna Sullivan Jones Email: shannasjones@msn.com

Tierney Clan
Project administrator: Mr. Cahir Tierney Email: otighearnaigh@eircom.net

Weadick – Mac Mhadóc
Website: See Register of Clans