Irish surnames starting with G

The G names in brief

• Gaffney · Ó Gamhna · Gaelic sept
  Descendant of Gamhain, 'calf'. Woulfe says Ó Gamhna was formerly common in Ormond, south Leinster and north Connacht, and generally anglicised Gaffney, though sometimes disguised as Caulfield. Gaffney also stands for two other Irish names he lists, Mac Gamhna and Mag Fhachtna, so one English spelling covers more than one family.
• Gallagher · Ó Gallchobhair · Gaelic sept
  Descendant of Gallchobhar, 'foreign help'. Gallchobhar is foreign help, and the family traced their descent from Maolchobha, a 7th-century king of Ireland. They were marshals of O'Donnell's forces, and Woulfe has them taking a prominent part in every military movement of Cinel Conaill from the 14th century onward; a great many of them were Bishops of Raphoe and Derry besides.
• Galvin · Ó Gealbháin · Gaelic sept
  Descendant of Gealbhán, 'bright-white'. Gealbhán means bright-white. Woulfe describes Ó Gealbháin as a Dál gCais family, now numerous in Munster, especially Kerry, and also found in Roscommon.
• Ganley · Mag Sheanlaoich · Gaelic sept
  Son of the old hero, from seanlaoch. A variant of Mac Seanlaoich, Woulfe writes. The family was seated in Corca Achlann in Co.
• Garrahy · Mag Fhearadhaigh · Gaelic sept
  Son of Fearadhach, 'manly'. A not uncommon surname, Woulfe writes, especially in east Connacht, Tyrone and Antrim. In speech it was sometimes corrupted to Ó Giorraidhe and then wrongly 'translated' O'Hare or Hare, as if from giorria, a hare.
• Garvey · Ó Gairbhith · Gaelic sept
  Descendant of Gairbhith, 'rough peace'. Ó Gairbheith, from Gairbhíth, rough peace. Woulfe gives three families: chiefs of Uí Eachach Cobha, the barony of Iveagh in Down, of the Magennises' stock; an Oriel family, chiefs of Uí Breasail in Armagh until the MacCanns dispossessed them; and a branch of the Uí Cheinnsealaigh, chiefs of Uí Feilmeadha Thuaidh around Rathvilly in Carlow.
• Gaughan · Ó Gáibhtheacháin · Gaelic sept
  Descendant of Gáibhtheachán, 'plaintive'. Woulfe makes Ó Gáibhtheacháin a branch of the Uí Fiachrach, anciently chiefs of Calraighe Muighe hEleog, a district nearly the same as the parish of Crossmolina in Mayo. By his day it was pronounced Ó Gácháin, hence Gaughan, and very common in Mayo and Sligo.
• Gavin · Ó Gábháin · Gaelic septs (several)
  Descendant of Gábhadhán, a diminutive of gábhadh, ‘want, need, danger’. Woulfe says at least two distinct families bore the name, one from Munster and one from Connacht. The Munster family was a branch of the Corca Laoighdhe in south-west Cork.
• Gaynor · Mag Fhionnbhairr · Gaelic sept
  Son of Fionnbharr, 'fair-head'. The family took its name, Woulfe writes, from an ancestor Fionnbharr Ó Géaradháin who lived about the beginning of the 12th century. The head of the family was chief of Muinntear Gearadhain in north Longford down to the 17th century.
• Geoghegan · Mag Eochagáin · Gaelic sept
  Son of Eochagán, from Eochaidh — a name built on each, 'horse'. Mag Eochagáin, son of Eochagán. An ancient Westmeath family of the southern Uí Néill, descended from Fiacha, son of Niall of the Nine Hostages, whose clan name was Cinéal Fhiachach; in the 16th century their country was the barony of Moycashel.
• Geraghty · Mag Oireachtaigh · Gaelic sept
  Son of Oireachtach, 'member of an assembly'. An ancient Connacht family of the same stock as the O'Connors, Woulfe writes, chiefs of Muinntear Roduibh in Roscommon until dispossessed around the middle of the 16th century. They were originally Ó Roduibh, until towards the end of the 12th century the descendants of Oireachtach Ó Roduibh took his name for their own.
• Gibney · Ó Gibne · Gaelic sept
  Descendant of Gibne, ‘hound’. A well-known surname in Meath and Cavan, in Woulfe's words.
• Gill · Mac an Ghoill · Norse-Gaelic
  Son of the foreigner. Mac an Ghoill, son of the foreigner. Woulfe explains it as an Irish surname given to the descendants of some of the early Anglo-Norman settlers, and found in every province; MacGill and Magill are other forms.
• Gilligan · Mac Giollagáin · Gaelic sept
  Son of Giollagán — 'youth, lad'. An Ulster surname peculiar to Antrim, Derry and Donegal, Woulfe writes. A separate Ó Giollagáin, scattered through Westmeath, Thomond and Connacht, also gives Gilligan.
• Gilsenan · Mac Giolla Seanáin · Gaelic sept
  Son of the servant of St Senan. A common surname in Meath, Cavan and Tyrone, Woulfe writes. By his time it was often hidden under the English names Nugent and Leonard, especially Nugent.
• Gleeson · Ó Glasáin · Gaelic sept
  Descendant of Glasán — from glas, grey. Woulfe calls Ó Glasáin a common surname across the south of Ireland, especially Cork, Limerick, Tipperary and Kilkenny, and notes it was by then pronounced Ó Gliasáin. He gives no single founding territory for it.
• Glennon · Mag Leannáin · Gaelic sept
  Son of Leannán, a diminutive of leann, ‘a cloak’. ‘A not uncommon Leinster surname’ is all Woulfe says. He names no family seat.
• Glynn · Mag Fhloinn · Gaelic sept
  Son of Flann, ‘ruddy’. A rather common surname in Connacht and Ulster, Woulfe writes. He treats it as a form of Mac Fhloinn and names no particular family or homeland.
• Gorman · Mac Gormáin · Gaelic sept
  Son of Gormán, 'the noble dark one'. Mac Gormáin, from gorm, blue. The MacGormans were lords of Uí Bairrche in the barony of Slievemargy in Laois until the Normans drove them out; some settled in Monaghan, others in Ibrickan in west Clare, where they became very numerous and their head was marshal of O'Brien's forces.
• Gormley · Ó Goirmleaghaigh · Gaelic sept
  Descendant of Goirmshleaghach, 'blue-spearman'. A distinguished Ulster family, Woulfe writes, chiefs of Cinel Moen, a sub-clan of the Cinéal Eoghain, first seated in the barony of Raphoe in Donegal. Driven out by the Cinéal Conaill in the 13th century, they crossed Lough Foyle and settled between Strabane and Derry, keeping considerable property until the Plantation of 1608.
• Grace · Grás · Norman
  Le gras — 'the stout'. Le gras, the fat. The Graces were an ancient and distinguished Kilkenny family, said to descend from Raymond le Gros, one of Strongbow's companions, and certainly among the earliest Norman settlers; the head of the family was Baron of Courtstown.
• Graham · — · Ulster Scots (Border)
  From Grantham, Lincolnshire — 'gravelly homestead'. A great family of the Scottish Borders, taken to the north of Ireland by settlers from Scotland and England in the 17th century. Woulfe also gives Graham as one anglicisation of the Irish Ó Gréacháin, so some Irish Grahams are Gaelic in origin.
• Greaney · Ó Gráinne · Gaelic sept
  Descendant of Gráinne — a woman's name. A rather common surname in Kerry and Galway, and, Woulfe points out, one of the few Irish surnames taken from a mother: Gráinne is a woman's name.
• Griffin · Ó Gríobhtha · Gaelic sept
  Descendant of Gríobhtha, 'griffin-like'. Ó Gríobhtha, from Gríobhtha, griffin-like, a fierce warrior. The family were Dál gCais, chiefs of Cinéal Cuallachta in the south-east of the barony of Inchiquin in Clare, with their castle at Ballygriffy.
• Grogan · Ó Gruagáin · Gaelic sept
  Descendant of Gruagán — from gruag, hair, or grúg, fierceness. Woulfe makes the Ó Gruagáin a Roscommon family, erenaghs of Elphin, now found in all parts of Ireland. He offers two meanings and does not choose: hair of the head, or fierceness.
• Guilfoyle · Mac Giolla Phóil · Gaelic sept
  Son of the servant of St Paul. An ancient family of Ely O'Carroll, Woulfe writes, chiefs of Clann Choinlegan near Shinrone in Offaly. Some took the English name Powell.

Also spelled with G

These are listed on the atlas under another spelling, but the G form is the one many families carry.