Ever wondered about the history behind your Irish last name? Where did your earliest ancestors come from? What was their profession? How did their name change over the centuries?

The following is Part III of a comprehensive list of the 300 most common Irish surnames.

For Part I, A - G, click here

For Part II, H - M, click here

O’Naghten, MacNaughton, MacCracken - There are a great many synonyms for O’Maghten (Ó Neachtain in Irish) in modern Ireland, including Naughtan, Naughton, Nochtin, Nocton, Knockton and even sometimes Connaughton (which is actually a different surname); while very strangely, some families of Naughton in Kerry have become Behane. The English name Norton is also used; the Nortons of Athlone, for example, are descended from feradach O’Naghten.

Nagle, Nangle - Nagle, or Neagle, is the form used by the Cork branch of the de Angulos who are called Nangle in North Connacht where, after the invasion at the end of the twelfth century, that famous Norman family became possessed of vast estates. The leading de Angulos adopted the surname MacCostello.

MacNally, Macanally - The usual form of this name in Irish is Mac an Fhailghigh, the derivation of which is obscure (in modern Irish failgheach means a poor man). These words are pronounced approximately MacAnally and this is quite a common alternative form of the name in English. In Connacht, where the name is found in Mayo and Roscommon, the prefix Mac is usually dropped, the simple form Nally being in use.

MacNamara - In Co. Clare, the homeland of the MacNamaras, the name is very common. In fact in everyday speech it is usually abbreviated to simple Mac: this is interesting because another Mac name, MacMahon, comes first in the numerical list of Co. Clare names, considerably ahead of MacNamara, which has second place, yet the abbreviation is never applied to MacMahon.

O'Neill: One of the proudest Irish names. Means descended from Niall, one of the great early Irish chieftains, Niall of the Nine Hostages. Niall can mean passionate or champion. Hugh O'Neill was one of the great irish chieftains. Eugene O'Neill was America's greatest dramatist.

O’Neilan, Neylan, Nyland - This name is seldom found with the O nowadays. It is usually spelled Neilan in Connacht and Neylan in Co. Clare - the O’Neilans being the original owners of Ballyally Castle. It originated in Thomond (Co. Clare): three of the names are listed as persons of importance in Co. Clare in the “Composition Book of Connacht” in 1585, though they are not described as chiefs.

O’Nolan - Nolan, seldom found nowadays with its prefix O, is the name of a sept of great antiquity which has always been associated with that part of Ireland which lies around the barony of Forth in Co. Carlow (not to be confused with the better known Forth in Co. Wexford). In pre-Norman days their chiefs, who held high hereditary office under the Kings of Leinster, were known as Princes of Foharta (modern Forth).

Nugent, Gilsenan - Though not an indigenous Irish surname, Nugent may be regarded as completely Irish today, since the Nugents have been important people in Ireland since the twelfth century when they came at the time of the Anglo-Norman invasion, their home country being France. They were then called de Nogent, i.e. of a place called Nogent in France, where they can trace their descent back to A.D. 930.

MacNulty - the derivation of many Irish surnames is open to doubt, but there is none about that of Macnulty: in Irish it is Mac an Ultaigh, i.e. son of the Ulsterman. An older anglicized form of the name, now rare, is MacAnulty. the MacNultys belong today, as they have done since the inception of surnames, to Donegal, which claims to be the most Irish part of Ireland.

O’Nunan, Noonan, Neenan - The name Noonan, which is also, but less frequently, spelled Nunan (the prefix O has not been resumed), belongs almost exclusively to the province of Munster and particularly to Co. Cork, where it originated. In modern Irish it is Ó Nuanáin: this is a corrupt or contracted form of the older Ó h-Ion-mhaineáin, of which the anglicized form of O’Hinunane, now obsolete, is approximately a phonetic rendering.

O’Phelan, Whelan - The name Whelan must be dealt with in conjunction with Phelan, as they are anglicized variants of the same Gaelic surname, viz. Ó Failáin, which itself has variant forms such as Ó Faoiláin and Ó hAoláin. Whelan is more common than Phelan: it stands seventy-ninth in the list of the hundred commonest names in Ireland. With Phelan added, the name takes forty-fourth place, with an estimated population of about twelve thousand persons. O'Phelan comes from the word faol, which means wolf.

Plunkett - The name Plunkett or Plunket is of French origin, not danish as often stated: it is a corruption of blanchet, derived from blanc, white. Though not an indigenous Gaelic surname it is one of those introduced into Ireland at the time of the Anglo-Norman invasion which has become exclusively Irish, for Plunkett is not found elsewhere except in the case of exiles of Irish stock.

Power - Though not Gaelic in origin, Power is one of the class of hibernicized names (like Burke and Walsh) which may be regarded as one hundred percent Irish. The name is now one of the most common in Ireland - it is estimated that there about eleven thousand Powers in the country today. The name came with the Normans in Strongbow’s twelfth century invasion. It comes from a nickname of 'poor man' or 'pauper.'

Prendergast, Pender - Maurice de Prendergast, whose name was taken from a village in Pembrokeshire, came to Ireland with Strongbow and was one of the leading Anglo-Norman invaders who obtained extensive grants of land in various parts of the south and west of the country. His descendants were seated near Waterford and in south Mayo, districts in which the name has always subsequently been found.

Purcell - Purcell is usually regarded as an Irish name, though the most famous man so called, composer Henry Purcell, was an Englishman. Both English and Irish Purcells are of Norman descent, the latter being found mostly in the contiguous counties of Kilkenny and Tipperary. The picturesque ruined castle of Loughmoe, the seat of the head of the family, is a well-known landmark near Thurles, to be seen from a main line railway between Dublin and Cork.

MacQuaid - The origin of the name MacQuaid, of which Mac Uaid is the form used in Irish, is obscure. It has long been well known in Co. Monaghan which is its principal location today. As MacQuaid, Mac Quade and MacQuoad it appears frequently in the Hearth Money Rolls for Co. Monaghan and for Co. Armagh (1664-1667). In Irish it is MacUaid (son of Wat). It has been borne by two notable churchmen - Bernard John MacQuaid (1823-1909), first bishop of Rochester, USA, whose parents, Irish emigrants, were murdered; and Most Rev. John Charles MacQuaid.

MacQuillan - Though MacQuillan is not a name of Gaelic origin it came into existence in Ireland and is not found elsewhere except among emigrants from Ireland. The MacQuillans are of Norman-Welsh descent: they settled soon after the invasion in the territory called the Route (Co. Antrim), and were known as Lords of the Route with their chief residence at the Castle of Dunluce until their major defeat at the battle of Ora in 1563 and again in 1580 by Sorley Boy MacDonnell, when they were dispersed by the Macdonnells.

MacQuilly, Cox - Although Cox is a common English name the great majority of our Irish Coxes are of native Irish stock, Cox (Cocks) being derived by translation the Gaelic Mac an Choiligh (son of the cock or rooster), the alternative form in English being the phonetic MacQuilly. This sept is still more common in the county of its origin, which is Roscommon. They were coarbs of St. Barry at Kilbarry in that country.

O’Quinlan, Quinlevan, Kindellan - Quinlan is the Munster form of the Gaelic Ó Caoindealbháin which, in Leinster, where the sept originated, was usually anglicized as Kindellan, and in modern times as Conlan and Connellan. They were of distinguished origin, being of the southern Ui Neill, and the senior line of the descendants of Laoghaire, King of Ireland in St. Patrick’s Day. The sept, originally located in north Meath, was much reduced by the Anglo-Norman invasion, but they remained there until the defeat of James II. 

O’Quinn - Quinn is one of the most numerous Irish surnames, the number of people in Ireland so called at the present day being estimated at seventeen thousand: in the list of commonest surnames it occupies twentieth place in the country as a whole and first place in Co. Tyrone, though widespread in many counties. Tyrone is the place of origin of one of the five distinct septs of this name. The Gaelic form is O Cuinn, which means descendant of Conn.

O’Rafferty, Roarty, Raferty - Originally belonging to the adjacent counties of Donegal and Sligo, the O’Raffertys are now found in many parts of Ireland, though nowhere in large numbers. They are still associated with Co. Donegal where they were coarbs of St. Columcille in Tory Island. The name derives from Gaelic 'rath bheartach,' meaning 'propserity wielder.' 

MacRannall, Reynolds, Grannell - In Reynolds we have an example of a fine old Gaelic Irish surname which has been given as its usual anglicized form a common English one. In Irish it is Mac Raghnaill, Raghnall being the Gaelic equivalent of Randal or Reginald. The forms MacRannall and Grannell, also used in English, are of course, nearer to the original.

Redmond - Redmond is a name of Norman origin: the first in Ireland was Alexander Raymond, who was of the same stock as Raymond le Gros, one of the best known of the Anglo-Norman invaders. The name soon became Redmond. The family obtained considerable grants of land in Co. Wexford, and throughout the 780 years since they settled in Ireland they have always been associated with Wexford and prominent in its affairs.

O’Regan - Regan is listed among the hundred most numerous Irish surnames: it holds sixty-eighth place with a total estimated population of nine thousand two hundred and fifty persons at the present time. Fifty years ago few bearers of the name made use of their prefix O, but it has been resumed by many families, and the voter lists and directories now indicate that nearly forty percent are listed as O’Regan.

O’Reilly (O’Rahilly) - O’Reilly, in Irish Ó Raghailligh (descendant of Raghallach) was until recently much more commonly found without the prefix O. Reilly and O’Reilly constitute one of the most common names in Ireland, being among the first dozen in the list. The bulk of these come from Cavan and adjoining counties, the area to which they belong by origin, for they were for centuries the most powerful sept in Breffny, their head being chief of Breffny -O’Reilly and for a long time in the middle ages his influence extended well into Meath and Westmeath.

O'Rourke, O'Rorke, McRoric (also Drouke, Groarke, Roarke) - The name, which translates to "The descendant of Ruairc," is an old and established one. Ruairc was a Norse-Viking personal name dating to before the year 800. The Ruairc family held large estates in Breffny, now Cavan and West Leitrim. A strong military clan that sent many of its leaders abroad.

Rice, O’Mulcreevy - The name Rice in Ireland is of two very different origins. The Rices of Oriel, now found chiefly in Louth and Armagh - counties comprised in that area - are Gaelic, and are called Ó Maolcraoibhe in Irish. The anglicizing of this surname as Rice is curious: the word craobh from which the name is derived means a branch. In Co. Down in O’Donovan’s time families of the name were known both as Mulcreevy and Rice, not as expected.

O’Riordan, Rearden - The sept of O’Riordan originated in Co. Tipperary, but they migrated to Co. Cork at such an early date that they can be regarded as belonging to that county, where they are now far more numerous than anywhere else. The vital statistics are indeed quite remarkable in this respect: of 170 births recorded for a given year, 100 were in Co. Cork and 54 in the counties (Kerry and Limerick) adjoining their territory in northwest Cork, where they were “followers of the Lords of Muskerry.”

Roche, Rochfort - Although Roche is not an indigenous Gaelic Irish surname it can nevertheless be regarded as exclusively Irish today, being found in England only in Irish, and more rarely French, emigrant families. It is French in origin - de la roche (of the rock) - and came to Ireland at the time of the Anglo-Norman invasion in the twelfth century.

O’Rooney - In modern Ireland this name is seldom if ever found with the prefix O to which it is entitled, since it is Ó Ruanaidh in Irish. The O’Rooneys were a sept of Dromore (Co. Down) and today they are principally to be found in Ulster and the neighbouring county of Leitrim. Several notable ecclesiastics of the name appear in the history of the diocese of Dromore.


MacRory, Rogers, MacCrory - In the sixteenth and seventeenth centuries, as evidenced by the Tudor Fiants, by the census of 1659 and other records, the name MacRory was both numerous and ubiquitous; now it is rare. This is no doubt partly due to the fact that in the southern half of the country it has been turned into the common English name Rodgers or Rogers. MacRory was first found in Tyrone, where the family held an ancient seat from the middle ages.

Ryan, O’Mulrian - Ryan is amongst the ten most common surnames in Ireland with an estimated population of 27,500. Only a very small proportion of these use the prefix O. Subject to one exception, to be noticed later in this section, it is safe to say that the great majority of the twenty-seven thousand five hundred Ryans are really O’Mulryans - this earlier form of the name is, however, now almost obsolete. First found in Tipperary.

Sarsfield - This name is dear to all Irishmen on account of the picturesque career of one of our national heroes, Patrick Sarsfield (1650-1693). Highlights of the distinguished military career include the destruction of the Williamite siege train at Ballyneety, the defense of Limerick, and his death from wounds at Landen. The year before, he had been made a general in the French army. The name was first found in County Cork.

O’Scanlan, O’Scannell - There are at least two quite distinct septs whose descendants are now known as Scanlan. One is Ó Scannláin of Muster and the other Mac Scannláin of Oriel (Louth), neither of which has retained the prefix O or Mac in modern times. The latter are perpetuated in the place name Ballymascanlon near Dundalk.

O’Scully, Scullion - Though originally a Westmeath sept, as early as the twelfth century the Scullys were driven by Anglo-Norman pressure to co. Tipperary and may be regarded as belonging to Munster - birth statistics place them chiefly in Co. Cork today. A branch of the family retained its lands in Co. Dublin up to 1256 when the property of Willaim O’Scully passed into ecclesiastical possession.

O’Shannon, O Shanahan, Gilshenan, Giltenan - The Gaelic name of three distinct Irish families became anglicized as Shannon or O’Shannon. First there is Ó Seanáin (descendant of Senan, a personal name) of which we know little beyond the fact that it was associated with Counties Carlow and Wexford, where the name is now rare. Originally, Shannon was a nickname for someone 'possessing great wisdom,' or an elderly person. 

MacShanly - The prefix Mac was dropped as early as the middle of the seventeenth century. Occasionally, since that time, O has been prefixed to it, but quite erroneously, as it is truly a Mac name: Mac Seanlaoich in Irish. In modern Irish seanlaoch means old hero. The sept is of Co. Leitrim, the chief being known as MacShanly of Dromod.

O’Shaughnessy - The O’Shaughnessys (in Irish Ó Seachnasaigh) were a sept of considerable importance in the part of Co. Galway known as the barony of Kiltartan, where people with this name are still concentrated. The original Gaelic name is O Seachnasaigh.

O’Shea - O’Shea is included in the list of fifty most common surnames in Ireland with an estimated number of nearly twelve thousand persons. If we include Shea, Shee, and O’Shee (variants of the same name) in the total. In Irish it is Ó Séaghdha, meaning descendant of Séaghdha: this word means hawk-like and dauntless. The O’Sheas are primarily a Kerry sept.

O’Sheehan, Sheahan - Sheehan is one of Ireland’s very common surnames: combining the alternative spelling Sheehan (eight percent) and Sheahan (twenty percent), it holds the seventy-fifth place in the list thereof, with an estimated total population in Ireland today of about eight thousand five hundred persons of the name. Of these the great majority were born in Co. Cork or on its borders. The Gaelic form is O Siodhachain, deriving from the word 'siodhach' which means peaceful.

MacSheehy - This name is now particular to Munster, though it is was not found there before 1420 when the first of the family came to Co. Limerick, when they took service with the Earl of Desmond and established themselves near the town of Rathkeale. They are first heard of in Ireland as gallowglasses, and as such they fought with distinction in many battles, having come to Ireland in the fourteenth century from Scotland (where they were a branch of the MacDonnell clan). It is derived from the word 'sithigh' which means 'peace.'

O’Sheridan - The Sheridan family originated in Co. Longford, being Erenaghs of Granard, but later moved to the next county - Cavan - where they became devoted followers of the powerful O’Reillys. The name Ó Siirideáin in Irish, i.e. descendant of Siridean, a personal name.The Sheridans are now dispersed widely throughout every province, though less in Munster than elsewhere.

O’Shiel, Shields - By origin and by the test of present-day distribution of population, O’Shiel is an Ulster name. In Irish Ó Siadhail, it is usually anglicized as Shiels, Sheils, Shields or Sheilds rather than O’Shiel, and these forms are chiefly found in Counties Donegal, Derry, Antrim and Down. Though claiming descent from Niall of the Nine Hostages, the O’Shiels were known as a medical family, rather than as a territorial sept.

Skerrett - The Skerretts of Ballinduff, Co. Galway, and Finvarra, Co. Clare, have now died out in the make line - the last representative being Rev. Hyacinth Heffernan Skerrett, a priest. They were extensive landowners in both those counties eighty years ago. Some junior lines survive elsewhere, but the name is now rare.

O’Sullivan - In Irish O’Sullivan is Ó Súileabháin. The derivation of the name is in dispute among scholars. There is no doubt that the root word is súil (eye), but whether it is to be taken as one-eyed or hawk-eyed is left an open question. While not quite as numerous as Murphy and Kelly, Sullivan, which is by far the commonest surname in Munster, comes third in the list for all of Ireland.

MacSweeney - The statement that the MacSweenyes are of the same line as O’Neill is somewhat misleading because, though it is true that their eponymous ancestor was Suibhne O’Neill, this man was a chieftain in Argyle, and the MacSweenyes who later established themselves as three great septs in tirconnell (Donegal) did not do so until the fourteenth century. The name does derive from the Gaelic word "suibhne" which means pleasant. However there is no mention of them in the Annals before 1267, when both the Four Masters and the “Annals of Connacht” record the death of Murrough MacSweeney, who was grandson of Suibhne.

Taaffe - Taaffe was originally a Welsh name signifying David (the modern pet name Taffy). In Irish it is rendered Táth, pronounced Taa. Settling in Co. Louth soon after the Anglo-Norman invasion, the Taaffes, rapidly attained a position of considerable importance in the country and, though they never became numerous like so many of the Norman immigrants, they continued to be one of the most influential families in Ireland.

MacTiernan, MacKiernan - No less than thirty-three MacTiernans are mentioned in the “Annals of the Four Masters,” practically all of them Chiefs of Teallach Donnchadha (modern Tullyhunco, in the county of Cavan) or relatives. Though not much information is given about their exploits, the mere recording of so many obituaries indicates the importance of the sept throughout the three centuries from 1250 to 1550. The Gaelic form is "Tighearnain," deriving from 'tighearna' which means 'lord'

O’Tierney, Tiernan - The most important of the original O’Tierney septs was that of Co. Mayo, where their chiefs were lords of Carra. The name is now very scattered, found in every county of Munster and Connacht, while it is rare in Ulster, outside Donegal. In Mayo, Tierney and Tiernan have been used as synonyms and cases of this are also reported from Co. Clare. This name also derives from the Gaelic word for 'lord.'

Tobin - Though Tobin is not an indigenous Gaelic Irish name, the family may be regarded as completely hibernicized. Originally of Aubyn in France, they were first called de St. Aubyn. They came to Ireland in the wake of the Norman invasion and by 1200 they were settled in Counties Tipperary and Kilkenny, whence they spread in course of time to the neighbouring counties of Waterford and Cork.


O’Toole, Toal - the O’Tooles are remarkable for their unremitting resistance to English attempts to conquer Ireland from the late twelfth century, when the Anglo-Norman invasion took place, down to the end of the seventeenth century, when the country was finally subdued. Nor is the name absent from the Roll of Honour in 1798. Their territory, though near Dublin, the seat of government, was admirably suited to resistance on account of its wooded and mountainous nature. Derived from 'tuathal,' meaning 'people mighty.'

O’Tracy - It is easy to be misled with the surname Tracy, for it is borne by an ancient and noble English family (Barons Sudeley), who are descended from Saxon ancestry. Their surname, however is not Saxon, having been acquired from a female Norman line named after Traci, a place in France.

MacTraynor - The Gaelic Ulster surname Mac Thréinfhir - son of the strong man, or champion - is anglicized Traynor, also spelled Treanor and Trainor, without the Mac, though the prefix is retained in the variant MacCrainor, which is phonetically more correct, since the T is aspirated in the Irish form of the name. 

O’Trehy, Troy - Though not numerous in Ireland the name Troy is not uncommon in Co. Tipperary and surrounding areas. The location of this small sept (which originated in Co. Clare but did not remain there) was in the Clogheen district of Co. Tipperary: their association with that part of the country is perpetuated in the placename. 

Tully, MacAtilla, Flood - This name is fairly common in Counties Galway and Cavan but is rare elsewhere (except in the city of Dublin where, of course, names from all parts of Ireland are found). It was formerly MacTully, and the form MacAtilla is used today in some places which suggests that the name in Irish was MacTuile or Mac a’tuile, meaning 'son of the flood.'

O’Twomey - The name Twomey, usually without the prefix O, is now, as always, predominantly associated with Co. Cork. When found elsewhere it is often spelled Toomey. In the census of 1659 O’Twomy appears as the second most numerous surname in the barony of Barretts, Co. Cork, Murphy being then the most common there.

Wall - The name Wall is found in considerable numbers in the part of Munster that lies between Limerick and Waterford, and in the adjoining counties of Leinster. The name is common in England also. It is of Norman origin: its earliest form is duVal, i.e. of the valley, hence the form de Bhál in Irish. 

Walsh, Brannagh - Only three surnames (Murphy, Kelly and Sullivan) exceed Walsh in numerical strength among the population of Ireland. It is found in every county and is particularly strong in Mayo, where it has first place, and also in Galway, Cork, Wexford, Waterford and Kilkenny.

MacWard, Ward - Although Ward is a very common English name, the great majority of Irish Wards are native Irish in origin, the Gaelic form being Mac and Bháird, which means son of the bard - the pronunciation of these words is closely reproduced in the alternative form in English, viz. Macanward, also written MacAward and McWard. The Wards, as their name implies, were professional and hereditary bards.

Whelan Ó Faoláin - From faol, meaning wolf. A variant form of Phelan found in the country between Co. Tipperary and Co. Wexford. Whelan is also sometimes an abbreviation of Whelehan and occasionally a synonym of Hyland. Whelan is rare in Ulster.

Woulfe - The Woulfes, or Wolfes, are a family of Norman origin who first came to Ireland at the time of the invasion at the end of the twelfth century. In Irish the name is usually written de Bhulbh, but le would be more fitting than de since the Norman form is Le Woulf (the wolf).

Don't see your surname listed in Part III of the top 300 Irish surnames?

For Part I, A - G, click here

For Part II, H - M, click here