The following is a list of Irish clans that can be sourced from modern published sources.

Unlike Scottish clans which are defined by surnames recognized by Scottish law of the Court of the Lord Lyon, there is no definitive authority on which surnames are regarded as Irish clans.^[1]

Clans of Ireland organization

Clans of Ireland is a modern organization that was started in 1989 and has eligibility criteria for surnames to be included on their register of Irish clans. This includes that the family or clan can trace their ancestry back to before 1691 which is generally considered to mark the end of the clan based lineage system in Ireland. There can be more than one clan with the same surname if of a different ancestry.^[2] Clans of Ireland lists the following clans on their Register of Clans, some of whom have their own clan societies or associations:^[3]

• Boyle - Ó Baoighill / Ó Baoill
• Carty - Cartys of Connaught
• Connolly – Ó Conghaile
• Fitzpatrick / Mac Gilpatrick of the tribe of Cas – Mac Giolla Phádraig Dál gCais
• Fitzpatrick / Mac Gilpatrick of Leinster – Mac Giolla Phádraig Laighean
• Hackett of Leinster – Ó hAicéad Laighean
• Joyce of Joyce Country – Seoigh Duthaigh Seoghach
• Mac Cabe of Breffny – Mac Cába Breffny
• Mac Carty – Mác Cárthaigh
• Mac Curtin of Thomond – Mac Curtáin Thuamhumhan
• Mac Garvey of Ulster – Mac Gairbhith Ulaidh
• Mac Ginley of Donegal – Mag Fhionnghaile Dhún na nGall
• Mac Grath of Ulster – Mac Craith Ulaidh
• Mac Hale of Co. Mayo – Mac hÉil Condae Mhuigheo
• Mac Kenna of Truath – Mac Cionaoith
• Mac Laughlin of Donegal – Mac Lochlainn Dún na nGall
• Mac Mullen Leinster - Maoláin agus Mac Maoláin
• Mac Shane – Mac Seáin
• McCarty - Mac Carthaigh
• McGillycuddy of the Reeks
• McKernan - Mac Thighearnain
• Mannion of Soghan – Ó Mainnín Soghain
• Morgan of Roscommon
• Nolan – Ó Nualláin
• O'Boylan of Darty – Ó Baoighealláin
• O'Brosnan of Brosna – Ó Brosnacháin Brosnach
• O'Byrne of Leinster – Ó Broin Laighean
• Ó Cellaigh Dal gCais
• O'Colman – Ó Colmáin Uí Fiachrach Muaidhe
• O'Crowley of Cork – Ó Cruadhlaoich Corcaigh
• O'Dea of Dysert – Ó Deághaidh Dísert
• O'Dowd - Ó Dubhda
• O'Driscoll of Corca Laoidhe – Ó hEidersceoil Corcu Loígde
• O'Farrell of Annaly – Ó Fearghail Angaile
• O'Flanagan – Ó Flannagáin
• O'Halloran - Ó hAllmhuráin / Ó hAlluráin
• O'Higgins of Ballynary
• O'Lafferty of Tyrone – Ó Laithbheartaigh Tír Eoghain
• O'Malley Clan – Clann Ó Máille
• O'Mordha / O'Moore / Moore of Leinster
• O'Mulvihill of Connacht
• O'Neill – Ó Neill
• O'Sullivan of Munster – Ua Súileabháin Mhumhain
• O'Tierney – Ó Tighearnaigh
• Poole
• Quigley of Connacht - Ó Coigligh
• Redfern
• Roche
• Lydon
• Walker

LangSyne Publishers

LangSyne Publishers, who are based in Kilbarrack, Dublin, Ireland, have published individual books on the following Irish clan surnames and their histories: Barry, Boyle, Brady, Brennan, Burke, Byrne, Callaghan, Carroll, Casey, Cassidy, Clancy, Collins, Connolly, Coyle, Daly, Devlin, Doherty, Donnelly, Donovan, Doran, Doyle, Duffy, Dunne, Farrell, Fitzgerald, Fitzpatrick, Flaherty, Flanagan, Flynn, Foley, Gallagher, Griffin, Healy, Higgins, Hogan, Joyce, Kane, Kavanagh, Kelly, Kennedy, Kenny, Lynch, Maguire, Malone, McCarthy, McCormick, McDermott, McGrath, McGuigan, McKenna, McLoughlin, McMahon, McManus, McNamara, Moore, Moran, Mullan, Murphy, Nolan, O'Brien, O'Dowd, O'Dwyer, O'Grady, O'Halloran, O'Hara, O'Keeffe, O'Leary, O'Neill, O'Rourke, O'Shea, O'Connor, Quinn, Reagan, Reilly, Rooney, Ryan, Sheehan, Sheridan, Sullivan, Sweeney, Traynor, Walsh, Ward, Whelan.^[4]

John Grenham (1993)

John Grenham in his 1993 book, Clans and Families of Ireland: The Heritage and Heraldry of Irish Clans and Families, lists the following Irish clan surnames and gives at least a paragraph of information for each: Aherne, Allen, Armstrong, Barrett, Barry, Beatty, Bell, Boyd, Boyle, Bradley, Brady, Breen, Brennan, Browne, Buckley, Burke, Burns, Butler, Byrne, Cahill, Campbell, Carroll, Casey, Cassidy, Clancy, Clarke, Cleary, Coleman, Collins, Conlon, Connolly, Conway, Corcoran, Costello, Coughlan, Craig, Cronin, Crowley, Cullen, Cunningham, Curran, Daly, Delaney, Dempsey, Dillon, Doherty, Dolan, Donnelly, Doran, Dowd, Dowling, Doyle, Driscoll, Duffy, Duggan, Dunne, Dwyer, Egan, Fahy, Farrell, Ferguson, Finnegan, Fitzgerald, Fitzpatrick, Flaherty, Flanagan, Fleming, Flynn, Foley, Ford, Fox, Gallagher, Gorman, Graham, Greene, Griffin, Hall, Hamilton, Hayes, Healy, Hegarty, Hennessy, Henry, Hickey, Higgins, Hogan, Hughes, Hurley, Johnston, Jones, Joyce, Kane, Kavanagh, Keane, Kearney, Keating, Kelleher, Kelly, Kennedy, Kenny, Keogh, Kerr, Kiely, King, Leary, Lee, Lenehan, Lennon, Long, Lynch, Lyons, MacAuley, MacBride, MacCabe, McCann, MacCarthy, MacCormack, MacCullagh, MacDermot, MacDonagh, MacDonald, MacDonnell, MacEvoy, MacGillcuddy, MacGovern, MacGowan, MacGrath, MacGuiness, MacHugh, MacKenna, MacKean, MacLoughlin, MacMahon, MacManus, MacNally, MacNamara, Madden, MacGee, Maguire, Maher, Malone, Martin, Meehan, Molloy, Moloney, Monaghan, Mooney, Moore, Moran, Morgan, Moraiarty, Morris, Mullan, Mulligan, Murphy, Murray, Nolan, O'Brien, O'Callaghan, O'Connell, O'Connor, O'Donnell, O'Donoghue, O'Donovan, O'Grady, O'Hara, O'Keefe, O'Mahony, O'Neill, O'Rourke, O'Shea, O'Sullivan, O'Toole, Patterson, Power, Quigley, Quinn, Redmond, Regan, Reid, Reilly, Riordan, Robinson, Roche, Rogers, Rooney, Ryan, Scott, Sheehan, Sheridan, Smith, Stewart, Sweeney, Tobin, Wallace, Walsh, Whelan, White, Woods.^[5]