St. Finbar's Oratory at Gougane Barra, west of Macroom, Co. Cork; when the COVID-19 pandemic is over and it's safe to gather, we will hope to be able to make this our Gathering site! 


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Even heavy rain could not dampen spirits at the 2019 Gathering!

Coolcower House, Macroom, Co. Cork, Ireland

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Muintir Mathuna - The O Mahony Society, is the international association of members and friends of the O Mahony Clan. The O Mahonys (O Mathuna in Gaelic) descend from Mathuin (Mahon), son of Cian mac Maol Muadh, Prince of Raithleann, and Saidhb, daughter of Brian Boru. Mathuin became Prince of Raithleann and chief of the Ui Eachach Mumhan in 1014 A.D.


The O Mahony Society's purposes are to foster studies on the history of the Clan, to promote interest in Irish culture and heritage, to promote and encourage the restoration and preservation of the historical sites associated with the Clan, and to promote fellowship among members.


The Society's activities embrace historical and cultural events via social meetings, a periodic newsletter, and the O Mahony Journal. The programme includes an annual Gathering of the Clan each summer in Ireland, and a Get-Together in the United States, Australia, New Zealand, or other countries as possible. Society members residing in countries outside of Ireland develop additional programmes in areas of interest and/or where members are concentrated. 



More Info?

Inquire about the society, upcoming events, etc.:


​June 17-19, 2022 


Our 2022 Clan Gathering, marking the 67th Annual Gathering of the Clan, is planned for the weekend of June 17-19, 2022. 

Details are emerging and will be posted on the News and Events tab as soon as possible. 





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Membership is open to all associated with the Clan by blood or affection. The Society currently includes members in Ireland, the United Kingdom, France, Spain, the United States, Canada, Australia, and New Zealand, and welcomes Clan from around the world.


The annual membership dues are €30  for members in Ireland and the EU, and £25 Sterling for the United Kingdom. The dues for other diaspora members are U.S. $35.00. The subscription year runs from 1 July to 30 June of the following year.

Please go to the Join/Renew tab for additional details and options for the submission of dues. 









A growing awareness of family identity in recent years has lead to a universal searching for roots. The O Mahony Society was founded in 1955, partly in response to inquiries from overseas but chiefly because of a pressing need to tap in Ireland the oral tradition for the history of families who might still bear the individual sept names adopted by various groups of the O Mahony family. There were eight principal sept names, and five minor septs. The historian, Canon John O Mahony, recorded with a high degree of scholarship a remarkable account of the O Mahony septs of Kinelmeaky and Ivagha down to the 17th century. From thence, however, the record-keeping is meager. The Irish diaspora in the wake of oppression, poverty and famine left a gap in the legacy of family history: much of the oral tradition has gone unrecorded and whatever exists today perishes with the passing of each generation.


Requests for research of family ancestry continue to grow, and is undertaken wherever possible by members in different locations. Initially, members must conduct a thorough search of family records in their possession, consult parents, grandparents and relatives, inspect civil and church records, legal documents and other sources of recorded information such as newspapers and census reports. This advice applies particularly to members outside Ireland.


It is hoped that all members will participate in their family tree research and share that information (please see the Research tab for more information).   Annual meetings of the O Mahony Society in Ireland will always include a professional genealogical workshop.



In May, 2018, the Global Data Protection Regulations (GDPR) became effective throughout the European Union (EU).  These sweeping reforms, designed to provide protection of your electronic information, will impact us all.  PLEASE REFER TO THE COMPLETE PRIVACY POLICY.  ALL EU RESIDENTS WILL BE REQUIRED TO GIVE AN ANNUAL UPDATE TO THEIR AGREEMENT WITH THIS POLICY.  The easiest method of doing such is to login to the website at least once a year.

As always, The O Mahony Society honors your privacy. We will only use your personal information for official Society communications and will not share your information with any outside source without your prior written consent.


If you have questions about The O Mahony Society and the GDPR, please contact Runai Linda McConnell Baker at

The O Mahony Society is not responsible for the content of external websites linked to from its own pages nor does it guarantee in any way the quality, reliability or viewing suitability of such links. We have, however,  made every good faith effort to ensure that its links are relevant and suitable.

Updated  ONovember 3, 2021