Register of Clans 2019

Clans who wish to apply to be included in the Register of Clans should register online here


Clans not included on the Register of Clans have not registered/renewed their membership for the current year. We await contact from these clans and individuals who are interested in organising a clan.

Clans are listed according to the most common English version of the surname followed by the original Irish version. Please note that individual Clan Societies may differ in the spelling variations they use in English and Irish and that  where appropriate we have used the original prefix of O' and Mac but these are not always used with every variant of each Clan name or can sometimes be used differently e.g. Mc, Mac, Mag, M' etc.





Burke – De Búrca


Contact: Mr Eamonn de Búrca, 27, Priory Drive, Blackrock, Co. Dublin.  A94 V406

Caomhánach Laighean

Caomhánach is a famous branch of the MacMurroughs. The name is said to have been adopted by the first Caomhánach having been fostered by a successor of St. Caomhan.  Over 200 interpretations of the Irish name Caomhánach are known, including Cavanagh, Kavanagh, Cavanaugh, Kavanaugh, etc.




Contact: Mr. Fergus Kavanagh, 514 Orwell Park Way, Templeogue, Dublin 6W, Ireland.



Carty of Connaught – Ó Carthaigh Connacht 

Historically, the Cartys, often spelt as Carthy, or Ó Carthaigh in Irish, were recorded as being a dynasty of the Clann Cathail group of families in North Roscommon. The name derived from a king of Connaught called Cathail, who died in 735. The Ua Carthaigh were recorded as chief poets of Connaught under the famous O’Conor kings from 1067 to 1131. A later branch of the Clan established themselves as canons of the Premonstratensian monastery in Lough Key, Boyle from 1428 to 1517. A poet, Aodh Ollbhar Ua Carthaigh was also recorded in the mid-15th century, in Uí Maine territory (South Roscommon/East Galway). As centuries passed, the Clan spread out to surrounding counties in Connaught and the midlands. Today, the heaviest concentration of the name still exists in County Roscommon. Another separate unrelated clan of Cartys exist in Wexford. Carty is often confused with McCarthy from Munster but again is unrelated. Famous Cartys from County Roscommon include Brian Carthy, RTE sports presenter and Jack Carty, Connaught Rugby player.

Website: Cartys of Connaught on Facebook.


Contact:  Mr Thomas Carty, Rosmeen, Ballintober, Castlerea, Co.Roscommon.   

Connolly – Ó Conghaile

CONTACT:  Bartle Ó Conghaile, Ballynaxos, Dunganstown, Brittas Bay West, Co Wicklow.


Cassidy of Fermanagh – Ó Caiside Fhear Manach

A clan located in Fermanagh who provided Ollamhs and Physicians to the Maguires. In more recent
times members of this sept can be found in all parts of Ireland, although less so in Connacht.
Contact: Mrs. Nuala Cassidy CIOM, 19B Meadowbrook, Tullygally, Craigavon, County Armagh, BT65 5AA, Northern Ireland.

Cully – Ó Colla


Contact:  Séamus Uasal Ó Colla, Tallaght, Leinster, Ireland

Dixon / Dickson – Mac Riocaird

A Hiberno-Scottish Clan, whom Alexander Nisbet [1657-1725] describes as a Cadet Branch of Clan Keith.

This Cadet Branch, as Dicson of Symonston & Hazelside, were Hereditary Castellan's of the Douglas Clan, and accordingly the Family descends in unbroken Line, from Hervey de Keith, Great Marischal of Scotland, to the present day.

Firstly as 'Dickson' and latterly 'Dixon' this Family appears in Irish Fiants and other Records from 1537 onward.

Today Clan Members in Ireland are principally found in Dublin and in Co Meath, particularly Rathcore & Longwood in the latter, as well as immediately adjacent areas in Co Kildare.

FIRST CONTACT:-  Honorary Chieftain; Michael GA Dixon:
SECOND CONTACT:- Registrar & Webmaster Clan Dixon: Derek Dixon-Byrne

Fagan – Ó Faodhagáin


Email: or

Contact: The Association of the Fagan Tribes c/o Mr. Rick (Fagan) Kasparek, 2512 Camarie Avenue, Midland, TX 79705.

FitzGerald of Co. Tipperary – Mac Gearailt Thiobraid Árann

FitzGerald of Co. Tipperary – Mac Gearailt Thiobraid Árann

Contact: Mr. Maurice Joseph FitzGerald III, J.D. Alabama, USA.


Hackett of Leinster – Ó hAicéad Laighean

The Hacketts (of Norman origin) settled in Leinster in the 12th Century in Kildare, Kilkenny, Dublin, Wicklow and Carlow.

Contact: Cav. Uilliam Ó hAicéad   GCEG. MSt.J. FSAScot. BB.
Address: 10a Lefroy Street Coatbridge North Lanarkshire ML51PN Scotland



Haggerty of Ulster – Ó h-Éigeartaigh Uladh 

E-mail:  Francis Haggerty <

Contact: Francis Haggerty, 34 Ellados,  Emimi, 4630 Limassol, Cyprus

Hoban of Cenél Eoghain – Ó hÚbáin Cenél Eoghain

(O) Hoban Clan Ó hÚbáin,  a branch of the Cenél Eoghain who settled in Co. Mayo.

From the 17th century a branch of the Hobans had settled in Co. Kilkenny.


Contact: Baron Denis A. Hoban, 1930 Lawerance Ave West, Toronto Ontario, M9N-1H2, Canada.




Joyce of Joyce Country – Seoigh Duthaigh Seoghach

The Joyces are a family who are believed to have come to Ireland from Wales around the end of the twelfth century.  They became hibernicized and by the sixteenth century had acquired much land in West Connacht in a mountainous area generally referred to as Joyce Country. They are recognized as having been one of the fourteen Tribes of Galway.

Contact: Mr. Laurie Joyce,  16 Pickerel Ave, Clyde North, VIC 3978, Australia

Kelly Clan Association – Muintir Ui Cheallaigh


Contact: Mrs Bernadette Kelly

Keohanes of West Cork – Ó Ceocháin

Keohanes Ó Ceocháin of West Cork is a small sept peculiar to West Cork, a branch of the
Crowleys (Ó Cruadlaoich). In past centuries the surname was Crowley Keohane or Crowley Cohane, but in later years the primary surname was dropped and Keohane is now the version used in Ireland.

Contact: Mrs. Nora Keohane Hickey, Church Square, Kinsale, County Cork, Ireland.









Kilcrann of Leitrim – Mac Giolla Crann Liatroma

A small clan from South Leitrim and East Roscommon believed to be a branch of the Billrín Clan. Today only two groupings of the Kilcranns are found in Ireland, one at Corlaskagh near Mohill in Leitrim and the second just ten miles away at Cloonfad near Rooskey in Roscommon.




Contact: Rev. Fr. John Kilcrann CSSP, Provincialate, Temple Park, Richmond Ave South, Dublin 6



Mac Cabe of Breffny – Mac Cába Breffny

The Mac Cabes (Clann Cába) were a strong Gallowglass Clan who first appear in the Irish Annals in 1358 and who, by 1424, were recognised as Constables of the two Breffneys (Cavan and Leitrim), Fermanagh and Oriel (Monaghan)


Contact: Mr. Brian McCabe, Ivy Cottage, Johnstown, Naas, County Kildare, Ireland.




MacCostello of Galway MacGoisdelbh Gaillimh

Contact:  Mr Sean Kennedy Costello,

Address: 201 Wellesworth Drive, Toronto, Ontario, Canada.


Mac Curtin of Thomond – Mac Curtáin Thuamhumhan

This clan orignates in Thomond but later was found in Cork. Up to the end of the 16th century the English version of the name was MacCruttin. In the census of 1659 in Counties Cork, Kerry and Limerick similar sounding names such as Mac Curatine and O' Curataine were treated as synonymous although they are not the same clan.
Contact: Mr. Dan Curtin, 45 Bishop Nelson Road, Valatie, NY US 12184, phone 518-758-9480.

Mac Egan of Hy Many – Mac Aodhagáin Uí Maine

Mac Egan Clan Mac Aodhagáin (son of Egan) are an important family of brehons originally of Uí Maine later settled in Ormond.
Contact: Dr. Michael J.S. Egan CLJ, 10 Rathdown Crescent, Terenure, Dublin 6W, Ireland.
DNA Project in progress.

Mac Garvey of Ulster – Mac Gairbhith Ulaidh

The McGarvey Mac Gairbhith Septs Association currently represents the following Clans:

Ó Gairbhith of Donegal,
Mac Gairbhith of Armagh,
Ó Gairbhith.

Contact: Mayor Jamie McGarvey, 42, River St., Parry Sound, Ontario, Canada. P2A 2T6.


Email: Jamie McGarvey -







Mac Geoghegan of Westmeath – Mag Eochagáin na hIarmhí

(Mac) Geoghegan Clan Mag Eochagáin is one of the clans of the Southern Uí Néill.




Contact: Mr. James Geoghegan.





Mac Gilpatrick of Ulster – Mac Giolla Phádraig Ulaidh

Contact: Dr Mike Fitzpatrick, 731 South Titirangi Rd, Auckland 0604, New Zealand

Mac Ginley of Donegal – Mag Fhionnghaile Dhún na nGall

Mac Ginley Clan Mag Fhionnghaile is a Donegal Clan claiming descent from one who was "fair" or "valour".




Ginnell [Westmeath]; Ginnelly [Mayo].

Contact: Proinsias Mag Fhionnghaile, Teonraigh, Béal Átha Seanaidh, Tír Chonaill, Éire.

Mac Grath of Thomond – Mac Graith Tuadhmhuman

CONTACT: Mr. Dan McGrath, 47 Town Court, Dungarvan, Co. Waterford



Mac Grath of Ulster – MacCraith na Uladh

The MacGrath Clan were co-arbs who settled at a place known as Termon MacGrath in south-west Ulster.

Contact: Mr. Seán Alexander McGrath KM,

Mac Hale of Co. Mayo – Mac hÉil Condae Mhuigheo

Next Clan Gathering: 14-16 July 2020, Gateway Hotel, Swinford Co. Mayo



Contact:  Mr Shawn McHale,  49, Meadows Lane, Haverford, PA 19041, USA

Mac Kenna of Truath – Mac Cionaoith

Mac Kenna Clan Mac Cionaoith a branch of the Southern Uí Néill settled in County Monaghan where they were Lords of Truath.

Contact: Siobhan McKenna McQuillan, Clossagh Beg, Rockcorry, Co. Monaghan - Secretary
Email: OR

Mac Laughlin of Tirconnell – Mac Lochlainn Thír Chonaill

Mac Laughlin Clan Mac Lochlainn are a senior branch of the Northern Uí Néill and a leading sept of Tirconnell who's seat was originally at Inishowen .


Contact: Conor Brian McLaughlin, Fanaghan, Inver, Co. Donegal.

Mac Mullen – Mac Maoláin

Mac Mullen Mac Maoláin is a common surname in Ireland with more than one clan of the name.




Contact: Col. Lyn David McMullen, 21-125 Cabernet Drive Okanagan Falls, BC, Canada V0H1R3.

Mac Shane – Mac Seáin

Mac Shane Mac Seáin is equivalent to Johnson. In Ulster and Louth the Mac Shanes are a cadet branch of the O'Neills.

Contact name: Jameson  Johnson McShane
Address: Waldburg Strasse 45, 71032 Boblingen, Germany



Mannion of Soghan – Ó Mainnín Soghain

The Mannion Clan descend from Mainnín son of Flannabra, a tenth-century king of the Sogain people who dwelt in modern-day East Galway in medieval times. Mainnín was a direct descendant of an Ulster prince called Sogan Sálbuide son of Fiacha Araide, the 37th king of Ulster. Fiacha Araide and his descendants, the Dál nAraide, are depicted by the medieval Irish genealogists as having belonged to the Cruthin, an early band of settlers deemed to have reached Ireland about 600 BC.

The origin legend of the Sogain of East Galway informs us that their progenitor Sogan Sálbuide migrated from Ulster to Connacht, where the legendary Queen Medb granted him an extensive territory between the Clare river and the Suck, where he and his followers settled. This was the ancient tuath or kingdom of Sogan, over which the Ó Mainnín Clan ruled as kings and later as chiefs until the end of the Gaelic era in the seventeenth century.

The Ó Mainnín surname first appears in the Irish annals in 1135, when ‘Ó Mainnín, king of Sogan’ was slain at the battle of Áenach Máenmaige to the east of Loughrea. The tomb of the last known chief of the name of the Mannion Clan, John son of Melaghlin, can be seen in the impressive ruins of Kilconnell Abbey near Ballinasloe, where it is marked by an inscribed graveslab dated 1648.

Contact:  Dr. Joe Mannion, Bolag, Woodford, Co. Galway.

DNA project: in progress

Monaghan – Ó Manacháin


Contact: Kevin Monaghan, Beaghbeg, Caherlistrane Co Galway, Ireland

Mulqueen of Ballymulqueeny – Ó Maolchaoin Baile-Ui-Maolchaoine

A clan located in the Co. Clare district of Thomand in north Munster.


Contact: Mr. Niall Mulqueen, 49 Silchester Park, Glenageary, Co.Dublin 

Nolan – Ó Nualláin


Contact: Christopher A Nolan III, 67 Commons Road, Clermont, New York, 12526 USA

O'Boylan of Darty – Ó Baoighealláin

(O’) Boylan Clan of Darty – Ó Baoighealláin  

The Boylans are a sept of Darty (County Monaghan). Before being subdued by the MacMahons of Oriel they were influential from Fermanagh to Louth.



Contact: Mr. Peter Boylan, Jagdweg 37, 90562 Heroldsberg, Germany.

O'Brien of Thomond – Ó Briain

O'Brien Ó Briain are a Dalcassian clan who ruled the Kingdom of Thomond (Co. Clare and Co. Limerick) and later the Kingdom of Munster. The clan derive their name and historical important from the family of King Brian Boru. Today, the surname O'Brien is numerous across Ireland as well as in Munster.


Chief: Sir Conor Myles O'Brien, The O’Brien, Prince of Thomond, Chief of the Name, 18th Baron Inchiquin, 10th Baronet of Leamaneh.

Seat: Dromoland Castle.


O'Brosnan of Brosna – Ó Brosnacháin Brosnach

The O'Brosnan's are a small but significant clan originating in a place called Brosna in County Kerry. In fact, the name in Irish Ó Brosnacháin means "a son of the descendent from Brosna". Brosnan is one of a handful of locational surnames found in Ireland.

Contact: Mr. Paul Brosnan, Uisneach, New Road. Greystones, Co. Wicklow.


Clan website:

O'Byrne of Leinster – Ó Broin Laighean

O'Byrne Ó Broin is a foremost clan in east Leinster, prominent in Irish history, especially in the resistance to English conquest.


Contact: Dr. Emmett O'Byrne, Hon Chief,  O'Byrne Solicitors, Office C25, Wicklow Enterprise Centre, The
Murrough, Wicklow Town, Co Wicklow.




O'Carroll of Oriel – Ó Cearbhaill Oirialla

O'Carroll Oriel Ó Cearbhaill Oirialla is an important clan who anciently ruled the Kingdom of Oriel (Co. Louth and Co. Monaghan).

Chief: Dr. Vincent J. O Carroll Oriel.



Contact: Dr Vincent J H O Carroll Oriel, Fairfield House, off Newbridge Avenue, Sandymount, Dublin 4.

O'Cleary of Co. Donegal – Clann Uí Chléirigh 


Contact: Mr. Fergus Cleary, 5 Main Street, Belleek, Co. Fermanagh BT93 3FY

O'Crowley of Cork – Ó Cruadhlaoich Corcaigh

O'Crowley Ó Cruadhlaoich derive their name from the Irish for hard (cruadh) hero (laoch). The clan originate in Moylurg in Connacht but migrated to West Cork where they became a leading clan.



Contact: Mr. James Crowley, Knocknagallagher, Bandon, Co. Cork.

DNA Project in progress

O'Dea of Dysert – Ó Deághaidh Dísert

O'Dea Ó Deághaidh Dísert is a Dalcassian clan based around their main seat at Dysert (Co. Clare). O'Dea is a name associated almost exclusively with the County Clare and the areas such as Limerick City and North Tipperary which immediately adjoin it. It is not a common name anywhere and even in County Clare is not numerous outside the part of the county where it originated. This is indicated by the place names Tully O'Dea and Dysert O'Dea, the site of a famous battle in 1318. The head of the clan was chief of a considerable territory comprising much of the Barony of Inchiquin.




Contact: Mr. Shane O’Dea 45, Carysfort Park, Blackrock, Co. Dublin.

O'Donnell of Tyrconnell – Ó Domhnaill Tír Chonaill


O'Donnell of Tyrconnell – Ó Domhnaill Tír Chonaill is the ruling clan of the ancient Kingdom of Tyrconnell who reigned until the completion of the English Conquest of Ireland in 1601. The clan's seat today remains focused mostly around County Donegal (with prominent branches in the Diaspora) but originally the Kingdom of Tyrconnell included all of Donegal and parts of Sligo, Leitrim, Fermanagh Tyrone and Southern Derry. The main seat of the clan's chiefly family is Donegal Castle.


Chief of the Name: Rev. Fr. Hugh O'Donnell, OFM, KM.

Tanaist: S.E. Don Hugo O'Donnell y Duque de Estrada,  KM, Duke of Tetuan.




Contact:  Mr. Vincent O'Donnell, Inver, County Donegal, Ireland.


O'Donoghue Society – Cuman Ó Donnchadha

The O'Donoghue Society was established to represent the following distinct O'Donoghue Clans:


Eoghanacht Chaisil Ó Donnchadha of County Tipperary,

Eoghanacht Raithlinn Ó Donnchadha /Uí Eachach Mhumhan/Cinéal Laoghaire,

Uí Dhonnchadha of Breifne,

Uí Dhonnchadha of Ossory,

Uí Dhúnchadha of counties Wicklow and Dublin,

Uí Dhúnchadha of Fine Gall of County Meath,

Uí Dhonnchadha of Teallach Modhárain,

Ó Donnchadha of the Uí Cormaic of County Galway,

Ó Donnchadha of the Uí Fhiachrach of counties Mayo and Sligo,

Eoghanacht Ninussa Ó Donnchadha of County Clare,

Uí Dhonnchadha of the Déisi Mhumhan


Patron of the Society: Geoffrey Vincent O'Donoghue, The O'Donoghue of the Glens, Lord of Glenfesk.




Contact: Mr. Rod O'Donoghue 30 Canonbury Park South, London N1 2FN, England


O'Dowd – Ó Dubhda Uí Fiachrach Muaidhe

The O'Dowd - Ó Dubhda clan traces its descent from Fiachra, brother of Niall of the Nine Hostages, through Daithi, the last pagan King of Ireland who, legend has it, was killed by a bolt of lightning as he led an army to the foot of the Alps in 455AD. For centuries they were the leading sept of the Uí Fiachrach Muaidhe  a tribal group that occupied part of the modern counties of Mayo and Sligo. The Uí Fiachrach provided successive kings of Connacht for a long period, but their sphere of influence became confined to North Connacht. In the late 10th century, their king was named Aedh Ua Dubhda (Hugh O'Dooda). He is recorded as having 'died an untroubled death' in the year 982, making this surname one of the oldest in Europe. His grandson, Maelruanaidh, who died in 1005 had the title of Lord of Hy Fiachrach.

Contact: Kieran O'Dowd

Address: 23134 Buckingham Street, Dearborn, Michigan, USA.





O'Driscoll of Corca Laoidhe – Ó hEidersceoil Corcu Loígde

O'Driscoll Ó hEidersceoil is an Anglicized form of the Gaelic Ó hEidirsceóil which is has the meaning of "diplomat" or "interpreter." The clan were based in Corcu Laídge where they were Kings.



Contact: Mrs Marion (O'Driscoll)Bushe, Bushes Bar, Baltimore, West Cork, Ireland

DNA Project in progress.

O'Dwyer Kilnamanagh – Ó Duibhir Coill na Manach

O'Dwyer/Dwyer of Kilnamanagh (in Irish O'Duibhir) are an ancient Irish clan who had the lordship of a region known as Kilnamanagh ("Wood of the monks") which straddled the modern Limerick/Tipperary border, and the highest density of the surname can still be found in that area. The territory was lost to the clan in the aftermath of the Cromwellian wars of the mid-seventeenth century, following the ill-fated capture of Cashel, the ancient Celtic seat of the Munster kings, by Philip O'Dwyer, the last clan chief. The clan was scattered to mainland Europe, forming part of that famous exodus known as the flight of the 'Wild Geese'.

Contact: Pádraig Uasal Ó Duibhir, Coismeagmór, Na Forbacha, An Spidéal.Co Na Gaillimhe

O'Farrell of Annaly – Ó Fearghail Angaile

O'Farrell Ó Fearghail means "man of valour". This clan were numerous and important in Annaly and had their chief seat at Longfordm which was known as Longphort Uí Fhearghail (O'Farrell's fort). 




Contact: Ballymacormack Longford Co Longford

O'Flanagan of Upperthird – Ó Flannagáin Uachtar Tíre

O'Flanagan Ó Flannagáin where Lords of Uachtar Tíre (Upperthird) which is located in County Waterford near Carrick-on-Suir. The O'Flanagans of Upperthird were dispossessed shortly after the English invasion by the family of Le Poer (now "Power"), who still possess a large portion of that territory




Contact: Jy Flanagan (Ard-Rúnaí), 8 Melyra St. Grenfell, NSW, Australia, 2810.

O'Flanagan – Ó Flannagáin

Flanagan is the name of at least five distinct and unrelated Irish Clans.

Flanagan of TuathRatha  (Fermanagh)

Flanagan of Clann Chathail (Roscommon)

Flanagan of Comair and Teffia (Westmeath)

Flanagan of Cinel Arga (Offaly)

All of the above Clans are represented by the Flanagan Clans Society

Contact details:

Address: Granuaile O'Flanagan,55 Soi Ladphra 35, Baan Supar Apt, Room 405, Chan Kasem, Chatuchak, Bangkok, Thailand 10900


See separate listing for Flanagan of Upperthird (Waterford).

O'Gara of Coolavin – Ó Gadhra Cúil Ó bhFinn

O'Gara Ó Gadhra means descendant of Gadhra' (an old Irish personal name, perhaps from gadhar, a dog, mastiff); the name of a Connacht family, of the same stock as the O'Haras of Leyney. Both families are descended from Lugh, son of Cormac Gaileng, and had from him the common clan-name of Luighne. When the two families separated, about the end of the tenth century, they divided this territory between them, the O'Haras taking the northern, or Sligo, portion, and the O'Garas the southern, in Co. Mayo. The O'Garas were then styled lords of Sliabh Lugha, but after the English invasion of Connacht they were driven out of this territory and forced to seek a new settlement. This they acquired in the district anciently known as Greagraidhe, and now as the barony of Coolavin, in Co. Sligo, from which in later times they were known as lords of Coolavin.



Contact: Mrs. Maura O'Gara-O'Riordan, 3 Cherry Park, Newcastle, Galway City, Ireland.

DNA Project in progress.

O'Higgins of Cenel Fiachach – Ó hUigin Cenél Fiachach

O'Higgins Ó hUigin  is a clan which claims descent from Cenél Fiachach a branch of the Southern Uí Néill.  The Clan were initially settled in the ancient Kingdoms of Brega and Mide before a branch migrated in the 12th century to Connacht. Principal seats were established in Westmeath at Kilbeg and in Sligo at Dooghorne, Monteige, and Ballynary.

Patron: Karl O'Higgins, The O'Higgins of Ballynary.


DNA project in progress.

O'Hosey of Fermanagh – Ó hEodhusa Fhear Manach

O'Hosey, Husey Ó hEaodhusa were an important bardic family attached to the Maguires of Fermanagh.
Contact: Mr. Robert B. Hosey, 5757 Bermuda Drive, Walbridge Ohio 43465, U.S.A. DNA project in progress.

O'Kearney of Derry – Ó Cearnaigh Doire

The O'Kearney clan were Erenaghs of Derry.


Contact: Dr. Chris Cairney

c/o Department of English, Middle Georgia State College,

1100 2nd St. SE, Cochran, GA 31014.




O'Lafferty of Tyrone – Ó Laithbheartaigh Tír Eoghain

O'Lafferty Ó Laithbheartaigh are a clan of Ulster described in the Annals of the Four Masters as the "Tanists of Tyrone".



Contact: Jamie Lafferty Richey 544 Windy Road Mount Juliet, TN 37122

O Mahony Society – Muintir Mhathúna

O Mahony Ó Mathúna were Cenél nÁeda princes of the ancient Eóganacht Raithlind. They were also for a period kings of Munster and Desmond, and take their name from Mathgamain, son of Cian, son of Máel Muad mac Brain, King of Munster from around 960 to 970, and then again from 976 to 978. From 970 to 976 he was king of Desmond. His son Cian became a close ally of Brian Bóruma and married his daughter Sadb. From this marriage descend the O'Mahonys.


Contact: Dr. Dermot O Mahoney, Rosbrin, 27, Woodlands, Montenotte, Cork, Ireland

O'Lalor of Leix – Ó Leathlobhair Laoise

O'Lalor (Lawlor) Ó Leathlobhair are one of the "Seven Septs of Leix" who's seat was at the Rock of Dunamase.

Contact: Mary Carmody, Rossleighan, Portlaoise, Co Laois.

O'Malley Clan – Clann Ó Máille



Contact: Mr. Don O'Malley

O'Mulpatrick of Breifne – Ó Maol Phádraig Breifne

O'Mulvihill of Connacht – Ó Maoilmhichil Connachta

O'Mulvihill Ó Maoilmhichil means "devotee of St. Michael" and originates in Connacht where they were an important clan. The name has also evolved over the years to Mitchell.




Contact: Thomas C. Mulvihill

DNA Project in progress.

O'Neill – Ó Neill

(O) Neill Ó Néill is a surname that is numerous throughout Ireland especially in Tyrone and Antrim. The Association of O'Neill Clans was established in 2007 and represents the following O'Neill Clans:


O'Neill of Tyrone

O'Neill of Fews

O'Neill of Clandaboy

O'Neill of Leinster i.e Carlow

O'Neill of Munster i.e. Decies and Thomond.




Contact: The Association of O’Neill Clans,

c/o Seán O’Neill, Clifton, 48 Castle Ave., Clontarf, Dublin 3, Ireland.




O'Reilly Breifne – Bréifne Ó Raghallaigh

O'Reilly Clan ruled a region known as Bréifne O'Reilly which covered most of the  modern county of Cavan. At one stage the clan's territory extended into Meath and Westmeath, and were Chiefs of all of Bréifne at some points in history.


Contact: Chevalier Brendan O'Reilly KCHS.

Address: 34 Broadmeadow Green, Ashbourne, Co. Meath.







O'Shaughnessy of Kiltartan – Ó Seachnasaigh Cill Tartan

O'Shaughnessy Ó Seachnasaigh are a branch of the Southern Uí Fiachrach said to be descended from Daithí who was the last pagan King of Ireland. The clan's seat is at Kiltartan in Galway.



Contact: 6 Whitehall Road, Aghagallon, Lurgan, BT 67 OAE

O'Sullivan of Munster – Ua Súileabháin Mhumhain

O'Sullivan Ó Súieabháin  originated in South Tipperary before they were forced Westward during the Anglo-Norman invasion where they became one of the leading clans of Munster Eoghanacht. There are a number of sub branches represented by the clan association including:

O'Sullivan Mór

O'Sullivan Beare

O'Sullivan MacCragh

Mac Fineen Duff (extinct)

The cadet clan of MacGillycuddy of Reeks evolved into a separate clan and are listed separately on the Register of Clans.




O'Tierney – Ó Tighearnaigh

O'Tierney Ó Tighearnaigh derived from the Gaelic word tighearnach meaning “lord” or “lordly”.  Tighearnach, sometimes spelt Tigernaich or Tigernach or even Tignarach was a popular given name in ancient Ireland. The O'Tierney Clans Society was formed in 1990 to represent the following main septs of the name:

O'Tierney Chiefs of Farney (Armagh)

O'Tierney Chiefs and Lords of Ceara (Mayo)

O'Tierney Kings of Bréaga

Fearran O'Tierney (Tipperary)

O'Tierney of Corcu Modruad (Clare)



Contact: Mr. Cathaoir Ó Tighearnaigh, Naomh Antoine, 53 Árd Aoibhinn, Athenry, County Galway, Ireland.

DNA Project in progress.

Poole -

Clan Poole, a cadet branch and descendants of Mag Uidhir (Mcguire's of Co Waterford and Fermanagh). Mag Uidhir also a cadet branch of their Parent house Clan Conla. There are Baptismal records of the Poole's in Ireland from the 17th century.

Contact: Mr. Darren Poole, 39 Bird Street Ince Wigan, WN22AZ, Lancashire, England



The Roche Clan were a Norman family who settled in Ireland Munster and Wexford.

Contact: Sir David Roche Bt

Address: 20 Lancaster Mews, London, W2 3QE, England.



Shortt – Mac Girr/MacAnghearre



Contact: James Shortt, Castleshort, Castle Cosey, Castelbellingham, Co. Louth.

Walker – Mac Siúbhlaigh


Contact: T Walker

Weadick MacMurrough – Mac Mhadóc mac Murchadha

Weadick Mac Mhadóc are a cadet branch of the MacMurrough Clan of Leinster. The Weadicks held their seat in south west Leinster and are numerous throughout Counties Wexford and Wicklow.

Vaddock, Waddock, Wadock, Waddick, Wadick, Waydock, Weadock, Weddick, Wedick.

Contact: Mr. Joe Weadick, 44 Fernhill, Arklow County Wicklow, Ireland.