by Andrew J. Morris

Edward MacLysaght's The Surnames of Ireland is THE authority on the origin and derivation of Irish surnames. MacLysaght was at one time the Chief Herald of Ireland, and Chairman of the Irish Manuscripts Commission. Other books he published on Irish surnames include Bibliography of Irish Family History, and Irish Families, Their Names, Arms and Origins and More Irish Families.

The Surnames of Ireland includes the Bibliography of Irish Family History and succinct descriptions of over 4,000 names, including those of Celtic/Gaelic, Norman, and Anglo-Irish origins. For names of Irish origins, he gives the original Irish/Gaelic form and its meaning. Usually he mentions the geographic location(s) the name is associated with, and sometimes has added historical notes. For names of Norman, English and Scottish origins, he often includes the time-frame when the name first appears in Irish records.

This is a handy reference for looking up the meanings and origins of Irish names, but the utility of this book doesn't end there. The introduction is an excellent guide to the general trends in Irish surnames. He dispels the myth that Mac is Scottish and Mc is Irish (or vice versa), describes the usage of the O prefix, and discusses the reasons for and nature of surname variant spellings and transformations.

Irish Families, Their Names, Arms and Origins and More Irish Families are fantastic resources if they have a name you are researching. There are also chapters expanding on the topics covered in the introduction in his The Surnames of Ireland -- the use of Mac and O, name distributions, and changes in names over time. For names covered by these books, he gives an extensive description of origins, history, arms, and distribution. Both of these books are now out of print, but it is often possible to locate used copies. [UPDATE: 'Irish Families' is back in print! Still the 1998 edition, but new printing.]

So, how do you know which names are in these books? Well I've listed below the names from Irish Families, Their Names, Arms and Origins. Names in parenthesis below are variant spellings or alternate names for the same families. As usual with Irish surnames, many of these names will be found without the O' or Mac prefix listed here. Also note that only a few of the most common variant spellings are listed.

The names are: O'Aherne (Hearne, O'Heffron), Athy, MacAuliffe, MacAwley (Cauley, Magawley).

Barrett (MacPadine, MacEvilly, Staunton), Barry, O'Beirne, Blake (Caddell, Blowick), Bodkin, O'Boland (Bolan), O'Boylan (Boyland), O'Boyle, MacBrady, O'Brallaghan (Bradley), O'Breen (MacBreen), O'Brennan (MacBrennan), MacBride (Kilbride), O'Brien, Browne, O'Buhilly (Buckley), Burke (Bourke, de Burgh), Butler, O'Byrne.

MacCabe, MacCafrey (MacCafferky), O'Cahill, O'Callaghan (Kelaghan), MacCann (Canny), O'Cannon (MacCannon), Carey (O'Keary, Carr), O'Carolan (Carleton), O'Carroll (MacCarroll, MacCarvill), MacCartan (Carton), MacCarthy, O'Casey (MacCasey), O'Cassidy, MacClancy (Glanchy), O'Clery (Clarke, MacClery, Clerkin), O'Coffey (Cowhig), MacCoghlan (O'Coughlan, Cohalan), MacColgan, O'Colman (Coleman, Clifford), O'Concannon, Condon, O'Connell (Gunning), O'Connellan (Conlan, Conlon), O'Connolly, O'Connor, O'Conry (Conroy, O'Mulconry, King), MacConsidine, MacConway (O'Conway, Conboy, Convey), O'Cooney, O'Corcoran (MacCorcoran), MacCormack (O'Cormacan), O'Corrigan (Carrigan), MacCostello (Nangle), MacCotter, MacCoy (MacCooey), Coyne (Kilcoyne, Kyne, Coen), Creagh, O'Crean (Crehan, Cregan), O'Crowley, O'Cullane (Collins), O'Cullen, O'Cullinan (Quillinane), Cummins (Comyn, Commons), O'Cunigan (MacCunigan, Cunningham, Dongan, Counihan), MacCunneen (O'Cunneen, Kenyon, Kinnane), MacCurley (Kerley, Turley, Terry), O'Curran, O'Curry (Corry), MacCurtin, Cusack.

Dalton, O'Daly, Darcy (O'Dorcey, MacDarcy), O'Dargan (Dorgan), O'Davoren, O'Dea, O'Delany (Delane, Dillane), O'Dempsey, MacDermot (Kermode), O'Devine (Davin, Devane), O'Devlin, Dillon, O'Dinneen (Downing), O'Doherty (MacDevitt), O'Dolan (Doolan), MacDonlevy (Dunleavy, Leavy), MacDonnell, O'Donnell, O'Donnellan (Donlon), O'Donnelly, MacDonogh (Donaghy), O'Donoghue (Donohoe, Dunphy), O'Donovan, O'Dooley, O'Doran (Dorrian), O'Dowd (Dowda, Doody, Duddy), O'Dowling, O'Downey (MacEldowney), Doyle (MacDowell), O'Driscoll, O'Duffy (Duhig, Dowey), O'Duggan (O'Dugan), O'Dunn (Dunn), O'Dwyer.

MacEgan (Keegan), MacElroy (MacGilroy, Kilroy), MacEnchroe (Crowe), MacEniry (Henry, O'Henry, Fitzhenry), MacEvoy (MacElwee, MacGilloway, MacVeagh).

Fagan, O'Fahy, O'Fallon (Falloon), O'Farrell (O'Ferrall), O'Farrelly (Farley), O'Feeney, O'Finn (Maginn), O'Finnegan, FitzGerald (Barron), FitzGibbon (Gibbons), Fitzpatrick (Kilpatrick), O'Flaherty (Laverty), O'Flanagan, O'Flannery, Fleming, O'Flynn (O'Lynn), O'Fogarty, O'Foley (MacSharry), Forde (MacKinnawe, Foran), Fox, French (de Freyne), O'Friel.

Gaffney (Caufield, O'Growney, Keveney, MacCarron), O'Gallagher, O'Galvin, MacGannon, O'Gara (Geary), MacGarry (Garrihy, O'Hehir, Hare), O'Garvey (MacGarvey, Garvin), MacGee, MacGenis (Guinness, Magennis), MacGeoghegan, MacGeraghty (Gerty), MacGilfoyle (Powell), MacGillycuddy (Archdeacon, Cody), O'Glissane (Gleeson), MacGorman (O'Gorman), O'Gormley (Grehan Grimes), MacGovern (Magauran), MacGowan (O'Gowan, Smith, MacGuane), O'Grady, MacGrath, O'Griffy (Griffin, Griffith), MacGuire (Maguire).

Hackett, O'Hagan (Aiken), MacHale, O'Halloran, O'Hanlon, O'Hanly, O'Hannon (Hanneen), O'Hanrahan (Hourihane), O'Hanraghty (Enright, Hanvey), O'Hara, Harrington (O'Harraughton), O'Hart, O'Hartigan, O'Hea (Hayes, Hughes), O'Healy (Hely, Kerrisk), O'Heffernan, O'Hegarty, O'Hennessy (Henchy), O'Heyne (Hynes), O'Hickey, O'Higgin, O'Hogan, O'Holohan (Holland, Mulholland, Hyland), O'Horan (Haren), O'Hosey (Hussey), O'Houneen (MacGlashan, Greene), MacHugh, O'Hurley (O'Murhila, Murrily, O'Herlihy).

MacInerney (Nerney, Kinnerk).

Jennings, Jordan, Joyce.

Kavanagh (Keevan), Keane (O'Kane, O'Cahan, MacCloskey, MacEvinney), O'Kearney (Carney), Keating (Keaty), O'Keeffe, O'Keenan, O'Kelleher, O'Kelly (Queally, O'Keily), MacKenna, O'Kennedy (Minnagh), O'Kenny, MacKeogh (Kehoe, O'Hoey, Hoy), MacKeon (MacKeown, Owens, Hone), O'Kieran (O'Kerin, Kearns, Kerrane), O'Kinneally (Quinnelly), Kinsella, O'Kirwan.

Lacy (de Lacy), Lally (O'Mulally), O'Lalor (Lawlor), O'Leary, O'Lee (MacAlee), O'Lenaghan (Linehan), O'Lennon (Linnane, Leonard, Linnegar, MacAlinion), O'Lonergan, O'Lorcan (Larkin), O'Loughlin (Loughnane), MacLoughlin, O'Lowry (Lavery), Lynch, O'Lyne (Lyons, Lehane, Lane), MacLysaght (MacAleese).

O'Madden (MacAvaddy, Madigan), MacMahon (Mohan, Vaughan), O'Mahony, O'Malley, O'Malone, Mangan (O'Mongan), Mannion (O'Mannin, Manning), Mannix (O'Mannis, O'Manihan, MacNeice), MacManus, Martin (Gilmartin), O'Meagher (Maher), O'Meara (O'Mara), O'Meehan (Meighan), O'Molloy (Miley), O'Molony (Maloughney), O'Monahan (Monks), O'Mooney (Meeny, Mainey), O'Moran, O'More (Moore), O'Moriarty (Murtagh), O'Moroney (Mulrooney), Morris (Fitzmaurice, Morrison), Morrissey, O'Mulcahy (Muckley), O'Mullan (O'Mellan, Mullen), O'Mulligan, O'Mulvihil (Melville, Mitchell), O'Murphy (O'Morchoe), MacMurrough, O'Murry (MacMurry, Murray, MacMorrow, Gilmore).

O'Naghten (MacNaughton), Nagle (Nangle), MacNally (MacAnally), MacNamara, O'Neilan (Neylan), O'Neill (Nihill), O'Nolan, Nugent (Gilsenan), MacNulty, O'Nunan (Noonan).

O'Phelan (Whelan), Plunkett, Power, Prendergast (Pender), Purcell.

MacQuaid, O'Quigley (Cogley), MacQuillan, MacQuilly (Cox), O'Quinlan (Quinlevan, Kindellan), O'Quinn.

O'Rafferty (Roarty, Raftery), MacRannall (Reynolds, Grannell), Redmond, O'Regan, O'Reilly (O'Rahilly), Rice (O'Mulcreevy), O'Riordan (Rearden), Roche (Rochfort), O'Rooney, MacRory (Rogers, MacCrory), O'Rourke, Ryan (O'Mulrian).

Sarsfield, O'Scanlan (O'Scannell), O'Scully, O'Shannon (O'Shanahan, Gilshenan, Giltenan), MacShanly, O'Shaughnessy, O'Shea (Shee), O'Sheehan (Sheahan), MacSheehy, O'Sheridan, O'Shiel (Shields), Skerrett, O'Sullivan, MacSweeney.

Taaffe, MacTiernan (MacKiernan), O'Tierney (Tiernan), Tobin, O'Toole (Toal), O'Tracy, Traynor, O'Trehy (Troy), Tully (MacAtilla, Flood), O'Twomey.