Irish surnames starting with K

The K names in brief

• Kavanagh · Caomhánach · Gaelic dynasty
  Follower of St Caomhán. Caomhánach means belonging to Caomhán. The family descend from Domhnall Caomhánach, son of Diarmait Mac Murchada, the king of Leinster who brought the Normans to Ireland; Domhnall got the name because he was fostered by the successor of St Caomhán at Kilcavan near Gorey.
• Kealy · Ó Caollaidhe · Gaelic sept
  Descendant of Caollaidhe. Woulfe finds three families: chiefs of Uí Bearchon in the barony of Ida, Kilkenny; chiefs of Crioch O mBuidhe in the barony of Ballyadams, Laois; and chiefs of Aolmhagh in Tipperary. He says the name was by then almost everywhere disguised as Kelly, and in Waterford became Queally.
• Keane · Ó Catháin · Gaelic sept
  Descendant of Cathán, 'little battler'. Cathán is a pet form of a name beginning Cath-, battle. The O'Cahans of Keenaght, a branch of the Cenél Eoghain, held the greater part of the present County Derry until their estates were confiscated in the Plantation of Ulster; they were O'Neill's chief urraghs, and their inauguration right was to toss a shoe over the new O'Neill's head.
• Kearney · Ó Cearnaigh / Ó Catharnaigh · Gaelic sept
  Descendant of Cearnach, 'victorious'. Cearnach means victorious. Woulfe gives three families: a Dál gCais family who rose to a high position at Cashel; a Uí Fiachrach family in Mayo with lands in Moygownagh and Balla; and a church family, erenaghs of Derry.
• Kearns · Ó Céirín · Gaelic sept
  Descendant of Céirín — from ciar, black. Woulfe identifies one family of Ó Céirín as lords of Ciarraighe Locha na nAirne in the barony of Costello, Mayo, and says there were doubtless several other families of the name elsewhere. Widespread already in the 16th century, it is found in every province, and he treats Ó Ciaráin, of Donegal and Imokilly in Cork, as the same surname.
• Keating · Céitinn · Norman-Welsh
  Possibly Welsh cethin, 'dusky'. Norman de Ketyng, from a place Woulfe admits he could not find. The Keatings were among the earliest Norman settlers, first in Wexford and then in Carlow, Kildare, Tipperary, Waterford and Cork.
• Keaveney · Mac Géibheannaigh · Gaelic sept
  Son of Géibheannach, 'fettered'. Originally a Fermanagh surname, Woulfe writes, found at the end of the 16th century in Sligo and Mayo, and by his time common in Connacht but very rare in Ulster.
• Keenan · Ó Cianáin · Gaelic learned family
  Descendant of Cianán, a diminutive of Cian, 'ancient'. Hereditary historians to the Maguires of Fermanagh — one of the families whose job was to remember, which is why we know as much as we do. Woulfe records them as still numerous throughout Ulster.
• Kehoe · Mac Eochaidh · Gaelic learned family
  Son of Eochaidh — from each, 'horse'. The Leinster branch, descended from Brandub mac Echach, king of Leinster in the sixth century, and chief poets of Leinster down to the seventeenth. The same name as Keogh, spelled the Wexford way.
• Kelleher · Ó Céileachair · Gaelic sept
  Descendant of Céileachar, 'companion-loving'. A Dalcassian family who moved south from Clare into Cork and Kerry, where the name is now concentrated around Millstreet and the Blackwater.
• Kelly · Ó Ceallaigh · Gaelic sept
  Descendant of Ceallach, 'bright-headed' or 'strife'. Ceallach is war, or contention, and Woulfe counts several distinct families of the name. The greatest were the Ó Ceallaigh of Uí Maine, a branch of the Oirghialla of Ulster who became one of the most powerful families in Connacht, ruling an extensive territory across east Galway and south Roscommon down to the reign of Elizabeth; Tadhg Mór Ó Ceallaigh fell at Clontarf in 1014.
• Kennedy · Ó Cinnéide · Gaelic sept
  Descendant of Cinnéidigh, 'helmeted head'. Cinnéidigh means helmeted head. The O'Kennedys of Ormond, a branch of the Dál gCais, descend from Cinnéidigh, son of Donnchuan, the brother of Brian Boru.
• Kenny · Ó Cionnaith · Gaelic sept
  Descendant of Cionnaith. Ó Cionaodha, descendant of Cionaodh, fire-sprung: the name of several separate families, common in the 16th century across Leinster and Munster and in Galway, Roscommon and Tyrone. Enda Kenny was Taoiseach from 2011 to 2017.
• Keogh · Mac Eochaidh · Gaelic learned family
  Son of Eochaidh — from each, 'horse'. Hereditary poets to the O'Kellys of Uí Maine and to the O'Byrnes of Wicklow. The root is Eochaidh, one of the oldest personal names in Ireland, built on the Old Irish ech, a horse — the same word standing behind Eoghan and behind the horse-lord in Ahern.
• Kerrigan · Ó Ciaragáin · Gaelic sept
  Descendant of Ciaragán — from ciar, black. A branch of the Uí Fiachrach, Woulfe writes, seated at Ballykerrigan in the parish of Balla, Mayo; before 1600 the name had spread into Donegal and Tyrone. In north Galway it was often 'translated' Comber or Comer, from a supposed link with cíor, a comb.
• Kiely · Ó Cadhla · Gaelic sept
  Descendant of Cadhla, 'graceful'. Cadhla means beautiful, comely or graceful. There were two families of Ó Cadhla: one in Connacht who were once chiefs of Connemara, and one in Thomond, chiefs of Tuath Luimnigh near Limerick city.
• Kiernan · Mac Tighearnáin · Gaelic sept
  Son of Tighearnán, 'little lord'. Woulfe finds three families: a branch of the O'Connors of Roscommon, from Tighearnán, grandson of Turlough Mór O'Connor, King of Ireland; a Breifne family of the O'Rourkes' stock, chiefs of Tullyhunco in west Cavan; and a Fermanagh family of the Maguires' stock, chiefs of Clann Fearghaile.
• Kilcoyne · Mac Giolla Chaoine · Gaelic sept
  Son of the servant of St Caoine, or of 'the gentle youth'. Woulfe found the name in the 16th century chiefly in Leitrim and around Dublin. He offers two readings, the gentle youth or servant of St Caoine, and thought Mac Giolla Chaoine the original, Mac Giolla Chaoin a clipped form.
• Killeen · Ó Cillín · Gaelic septs (several)
  Descendant of Cillín, a pet form of Ceallach. Woulfe says several distinct families in different parts of the country bore this name: in Clare, Galway, Mayo, Westmeath, Offaly, Kildare and Down. It was still found in all of them.
• Kinsella · Cinnsealach · Gaelic dynasty
  Of the Uí Cheinnsealaigh — the royal line of south Leinster. Cinnsealach, belonging to Uí Cheinnsealaigh in Wexford. The Kinsellas descend from Énna Cinnsealach, son of Diarmait Mac Murchada, King of Leinster at the time of the Norman invasion.
• Kirby · Ó Ciarmhaic · Gaelic sept
  Descendant of Ciarmhac, 'dark son'. Ciarmhac means black son. The Ó Ciarmhaic were an ancient East Limerick family, chiefs of Eoghanacht Áine around Knockainy until after the Norman invasion, and still numerous in Limerick and across Munster.
• Kirwan · Ó Ciardubháin · Gaelic sept
  Descendant of Ciardhubhán, 'the black-dark one'. One of the fourteen Tribes of Galway, and unlike most of them of Gaelic Irish rather than Norman origin.
• Kissane · Ó Casáin · Gaelic sept
  Descendant of Casán — from cas, curly. Woulfe places Ó Casáin first in Uí Maine, Co. Galway, where it was pronounced Ó Cosáin and anglicised Cussane or even Patterson.

Also spelled with K

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