O Keady - Irish / Ua Meiceidigh. An Ithian Corca Laoidhe Sept / Family branch, who had their territory in Co. Cork in Desmond / Des Mhumhain /  Southern Munster. Their name there was also corrupted to Mac Cedigh and Mac Eidigh.  Ancestors - *36.Lewy / Lughaidh, *35.Ith (Ithians).

Mac Keady or Mac Keadie or Mac Keddy or Mac Keedie or Mac Keedy or Mackeady - Irish / Mheic Ceadaigh / Ceadach (a personal name - cead / one hundred). An Irian Laeghis Ui Laoighis Sept / Family branch of the O More / O Moore / Ui Mordha who are also kinsmen to O Brophy / O Brofie / Ui Broithe, O Cashin / O Kissane / Ui Casain, O Deegan / Ui Duibhgainn, O Doran / O Dorrian / Ui Deoradhain, O Dowling / Ui Dunlaing, Mac Gahan / Mac Geehan / Mageehan / Mheic Gaethain, O Harrigan / O Harraghan / O Harahan / Ui hArraghain, Ui Liathain, O Lalor / O Lawlor / Ui Leathlobhair, Mac Lee / Mac Lea / Ui Laoidhigh, O Swords / O Sord / O Sourdes / O Suard / Ui Suaird who had their territory in Co. Laois in the mid - north - west of Southern Leinster. Ancestors - *83.Fachtna, *82.Milige, *81.Bran, *80.Eircc "hUbulchind," *79.Felim / Feidlimid mheic Finnchad, *78.Fiachach "Uanchind," *77.Daire, 76.Rossa, *75.Ogomain, *74.Fergus, *73.Muleist, *72.Fachtna, *71.Milige (Ui Baccan), *70.Intait, *69.Lugdach "Loichsi" / Laoiseach "Ceann Mor" the ancestor of the O More / Moore / Siol Morda Sept in Co. Laois (named for him) in the north - west of Southern Leinster who were among the ”7 Septs of Laois, *68.Conall "Cernach" - of the Victories the leader of the Knights of the Red Branch of Ulster who is the direct ancestor also of the Mac Guinness, Mac Gowan and many other Irian Families in the Ulster Province and the Connacht Province. (He was a contemporary of Cuchulainn), *67.Aimhirgin "Larghiunach," *66.Cas, *65.Fachtna, *64.Cathbladh, *63.Cionga,  *62.Rory / Ruaidri “Mor” / the Greater who died in 218 BC as the Irian 86th King of Tara / Erinn (Clann - na - Rory,*37.Ir (Irians). They are are now to be found mostly in Co. Galway in Southern Connacht as Mac Keady.

Mac Keaghan - Irish / Mheic Tadhgain. An Irian Conmaicne Magh Rein Muintir Anghaile Sept / Family branch of the O Farrells / O Ferralls / Ui Fearghaile Sept, who had their territory at Annually in Co. Longford in the north - east of Northern Leinster. Especially see - O Keegan.

Mac Keaghery or Geaghery or Mac Keefry - Irish / Mheic Fiachra. A Heremonian Ui Cobhthaigh Dal Cuinn "Northern" Ui Niaill Cenel nEogain Cenel Fearadhaigh Mheic Fiachra Sept / Family branch, who had their territory at Clogher in Co. Tyrone in Central Ulster. Kinsmen to the Clann Cathmhaoil / Mac Campbell / Mac Campell / Caldwell / Mac Cawell.) Ancestors - *89.Feradach, *88.Eogain the 1st King of Aileach (Cenel nEogain), *87.Niall of the Nine Hostages the 126th King of Tara / Ireland (Ui Niaill).

Mac Keaghry or Mac Keahery. See - Mac Keighry.

Mac Keague or Mac Teague or Mac Teige / Mac Thaidhg. They were in the Ulster  Province. There are at least 14 variant forms including Mac Cague, Mac Aig and Mac Haigh, which see.

Mac Keahan - Irish / Mheic Tadhgain. An Irian Conmaicne Magh Rein Muintir Anghaile Sept / Family branch of the O Farrell / O Ferrall / Ui Fearghaile Sept, who had their territory at Annually in Co. Longford in the north - east of Northern Leinster. Especially see - O Keegan.

Mac Keahan. See - Mac Keehan.

O Kealaghan or O Kealahan or O Keelaghan  / Ui Ceileachain - ceile / companion. A Heremonian Ui Cobhthaigh Dal Cuinn Colla da Crioch Ui Breasail Airthir / Orior / Airthir Siol Fiachra Cassan important Sept / Family branch who were the Chiefs of the Ui Breasail Sept. They were kinsmen to the Clann Fermaighe / Mac Cadden / Mac Cadigan / Mac Adam / Mac Adan / Mheic Acadhain, Muintir Caiseil / O Cashel / O Cassily / O Casley /  O Cassell / O Cassely / O Cushley / Ui Caisile, O Dullahan / O Dallaghan / O Dallahan / O Dallan / O Dolghan, O Kernaghan / O Kearnaghan / Ui Cearnachain, O Madigan / Ui Madadhain, O Trainor / O Trainer / O Trayner / Ui Threinfhir. They had their territory in the north of Co. Armagh in the south - east of the Ulster Province. Ancestors - *97.Buachalla, *96.Conor / Conchobar "Chorraig," *95.Mael "Duin," *94.Fingin, *93.Ronan, *92.Toole / Tuathal, *91.Ailella, *90.Conall, *89.Feicc, *88.Bressal, *87.Felim / Feidlimid, *86.Fiachra "Cassan," *85.Murray / Muiredach "Colla da Crioch / Focrith" - of the Two Countries, *84.Eochy / Echu "Doimhlen." *83.Cairbre "Liffeachair" the 116th King of Tara / Ireland. Some also changed their name to O Callaghan in Co. Westmeath in the south - west of Northern Leinster. Also see O Keelan, which was also used to abbreviate their name.  

O Kealy or O Queally - Irish / Ui Cadhla. An important Irian Conmaicne Mara Sept / Family branch, who had their territory in the Connemara in the west of Co. Galway in the Connacht Province. Kinsmen to Mac Conneely / Mac Neela, O Cloherty / Stone / Ui Clochartaigh, O Devany / Ui Dubhain, Mac Folan / Mac Fallon / Mac Foland / Mac Folane / Mheic Fualain. Ancestors - *79.Conmacc / Conmac (Conmaicne), *78.Oirbsen "Mor" /  Orsenmar after whom Loch Oirbsen is named, *64.Fergus mac Roich. *63. Ros / Rossa “Ruadh” the King of Ulster, *62.Rory "Mor" the 86th King of Tara / Erinn (Clann Rory), *37.Ir (Irians).

O Kealy or O Keally or O Keeley or O Kiely. A Heremonian Ui Laoghaire Cu Corb Sept / Family branch, whose territory was in Co. Laois in the mid - north - west of Southern Leinster. Ancestors - *86.Cu "Corb," *60.Leary / Laoghaire the 68th King of Tara / Ireland (Ui Laoghaire), *37.Heremon (Heremonians).

O Kealy or O Keally or O Keeley or O Kiely. which see - Irish / Ua Cadhla, who had their territory in Co. Waterford in the south - east of the Munster Province and nearby in Co. Limerick in the mid - north - west of Munster.

O Kealy or O Keally or O Keeley or O Kiely. Utilized also by some of the O Queallys, which see - Irish / Ua Caollaidhe, who had their territory in Co. Kilkenny in the south - west of Southern Leinster. Their territory there was taken over by the Anglo - Normans after that particular Invasion in the 12th Century AD.

O Kealy or O Keally or O Keeley or O Kiely. See - O Ceile. An  Ecclesiastic Sept who had their territory in Co. Meath and Co. Louth in the east of Northern Leinster,

O Kealy or O Keally or O Keeley or O Kiely. Used by the O Kellys - Irish / Ua Ceallaigh, which see, who had their territory in Co. Galway in the south - west of the Connacht Province who were the Chiefs of the Connemara there.

O Kean or O Keane - Irish / Ua Cein (Descended from Cian) A Sept / Family branch, who had their territory in Co. Waterford in the south - east of the Munster Province.

O Keane or O Kean - Irish / Ua Cathain - cath / battle. A Heremonian U Cobhthaigh Dal Cuinn 'Southern" Ui Fiachrach "Aidne" Sept / Family branch, who had their territory in the south of Co. Galway in Southern Connacht and nearby in Co. Clare in the north - west of the Munster Province. Ancestors - *87.Fiachra the original 2nd King of Connacht (Ui Fiachrach), *86.Eochy "Mugmedon" the 124th King of Tara / Ireland.

Mac Kean or O Keane or Mac Keon - Irish / Mheic Eogain. A Heremonian Ui Cobhthaigh Dal Cuinn "Northern" Ui Niaill Cenel nEogain Sept / Family branch, who had their territory in Co. Tyrone in Central Ulster. Ancestors - *104.Flaherty / Flaithbertach Ua Niaill, *103.Murtough / Muirchertach, *102.Donnell / Domhnaill O Niall the 34/37th King of Aileach and 168th King of Tara / Ireland,  *101.Murtough / Muirchertach the 33rd King of Aileach, *100.Niall "Glun Dubh" the 29th / 30th King of Aileach and 165th King of Tara / Ireland (O Neills of Ulster), *99.Aed "Findliath" the 25th King of Aileach and 163rd King of Tara / Ireland, *96.Niall "Frossach" the 19th King of Aileach and 157th King of Tara / Ireland, *95.Fergal the 17th King of Aileach and 151st King of Tara / Ireland, *94.Mael "Duin" the 14th King of Aileach, *93.Mael "Fithrich" the 10th King of Aileach, *92.Aed "Uaridnach" the 8th King of Aileach and 140th King of Tara / Ireland, *91.Donnell / Domhnall "Ilchelgach" the 4th King of Aileach and 134th King of Tara / Ireland, *90.Murtough / Muirchertach mac Ercae the 3rd King of Aileach and 131st King of Tara / Ireland, *89.Murray / Muiredach the 2nd King of Aileach, *88.Eogan the 1st King of Aileach (Cenel nEogain), *87.Niall of the Nine Hostages the 126th King of Tara / Ireland (Ui Niaill).

Mac Keane. Highland Scottish origins.- Gaelic Irish / Mheic Eain. A variant used for Eoin / John. They settled in Co. Donegal and nearby in Co. Derry in the north - east of the Ulster Province. See also Muckian.

Mac Keane or Mac Cahan - Irish / Mheic Cathain. A Co - Arb Sept / Family branch, who had their territory in the west of Co. Clare in Thomond / Tuaiscert Mhumhain  / Northern Munster where they were Co - Arbs of St. Senan. Also Chiefs nearby in Co. Tipperary in Ormond / Aur Mhumhain / Eastern Munster.