O Donegan or O Dunnigan - Irish / Ua Donnagain. An important Heremonian Ui Cobhthaigh Ui Conaire Muscraige Tri Maighe Sept / Family branch, who had their territory in the north - west of Co. Cork in (Muskerry of the 3 Plains) "O Donegans Country" in Desmond / Des Mhumhain / Southern Munster, which was eventually taken over by the Barrys who were Anglo - Norman Barons there. See also Dongan. Ancestors -*69.Conaire 11 (Ui Conaire), *60.Coffey / Cobhthach the 69th King of Tara / Erinn, *37.Heremon (Heremonians).

O Donegan or O Dunnigan - Irish / Ua Donnagain. An Erenagh Sept / Family branch, who had their territory in the south - west of Co. Cork around Beare in Desmond / Des Mhumhain / Southern Munster, which eventually came under the over lordship of the O Sullivans. See also O Dongan.

O Donegan or O Dunnigan - Irish / Ua Donnagain. A Sept / Family branch, who had their territory in Co. Roscommon in the east of the Connacht Province.

O Donegan or O Dunnigan - Irish / Ua Donnagain. A Sept / Family branch, who had their territory in the north of Co. Tipperary in the north - east of Ormond / Aur Mhumhain / Eastern Munster and the adjacent territory in Co. Limerick under Rory O Donnagain the King of Aradh eventually given over to the Mac I Briain of Ara, a son of 105.Brian "Boru" the King of Thomond, 41st King of Munster and 170th High King of Ireland.

O Donegan or O Donnegan or O Donnegane or O Dunnigan - Irish / Ua Donnagain. A Heremonian Ui Cobhthaigh Dal Cuinn Colla da Crioch Cenel Rochada Fernmag (Fer Fermaighe / Farney Sept / Family branch - who had their territory in Co. Monaghan in Southern Ulster. Now also indistinguishable from Mac Donegan. Ancestors - *107.Lethlobar, *106.Fogartach, *105.Murray / Muiredach, *104.Laidgnen, *103.Fogartach, *102.Duncan / Donncuan, *101.Fogartach, *100.Ruadrach, *99.Maoilfothartaigh, *98.Artrach, *97.Aitheachda, *96.Mailduib, *95.Maoilfothartaigh, *94.Cronan, *93.Fergus, *92.Nadsluaig, *91.Cairpre "Daim Argait," *90.Eochy / Echach, *89.Criffan / Crimthainn "Leith" / "Lethan," *88.Feicc, *87.Dega "Duirn," *86.Rochad / Rochatha, *85.Murray / Muiredach "Colla da Crioch" / "Focrith" - of the Two Countries, *84.Eochy / Echu "Doimhlen," *83.Cairbre "Liffeachair" the 116th King of Tara / Ireland.  

O Donegan or O Dunnigan - Irish / Ua Donnagain. A Sept / Family branch of the Crioch Dungan, who had their territory in Co. Westmeath in the south - west of Northern Leinster and adjacent territory in Co. Laois, Co. Offaly and Co. Kildare in Southern Leinster. Thomas Donegan was the English appointed Earl of Limerick.

Mac Donegan - Irish / Mheic Donnagain. A Sept / Family branch, who had their territory in Co. Down in the south - east of the Ulster Province. See also Dongan.

Donel -

O Donelan. A Heremonian Ui Cobhthaigh Dal Cuinn Colla Uais Ui Mheic Uais Ui Tuitre Sept / Family branch, who had their territory in the west of Loch Neagh in Co. Tyrone in Central Ulster and north - west of the loch at Loughinsholin in Co. Derry. Ancestors - *85.Carroll / Carioll "Colla Uais" the 121st King of Tara / Ireland, *84.Eochy / Echu "Doimhlen," *83.Cairbre "Liffeachair" the 116th King of Tara / Ireland. See especially - O Donnellan.

O Donevan. A Sept / Family branch, who had their territory in Co. Limerick in the mid - north - west of Thomond / Tuaisceart Mhumhain / Northern Munster.

Dongan. English Earls. They were in Co. Limerick in the mid - north - west of Thomond / Northern Munster and were also in Co. Kildare in Central Southern Leinster and Co. Dublin in the north - east of Southern Leinster.

O Donlan or O Donnellan, which see - Irish / Ua Domhnallain. A Heremonian Ui Cobhthaigh Dal Cuinn Ui Maine Sept / Family branch, who had their territory in the south - east of Co. Galway in Southern Connacht. Ancestors - *86.Maine "Mor"(Ui Maine), *85.Murray / Muiredach "Tireach" the 122nd King of Tara / Ireland, *80.Conn of the Hundred Battles the 110th King of Tara / Ireland (Dal Cuinn).

O or Mac Donlevy or O or Mac Dunlevy, which see - Irish / Mheic Duinnshliebhe. (Descended from a son of *109.Donn "Sliebe") A Dal Fiatach Sept / Family branch, who were Princes originally in their territory in Co. Down in the south - east of the Ulster Province where their territory was the kingdom of Ulaidh from which Ulster received its name. Later on they had their territory  in Co. Tyrone in Central Ulster. Ancestors - *109.Donn "Sliebe" the 56th King of Ulaid, *108.Eochy / Eochaidh the 52a King of Ulaid, *107.Niall the 52nd King of Ulaid, *106.Eochy / Eochaidh the 45th King of Ulaid, *105.Ardgal the 42nd King of Ulaid, *104.Matudan the 41st King of Ulaid, 103.Aed the 37th King of Ulaid, *102.Eochocan the 31st King of Ulaid, *101.Aed, *100.Eochy / Eochaidh the 24th King of Ulaid, *99.Fiachnae the 22nd King of Ulaid, *98.Aed "Rain" the 19th King of Ulaid, *97.Becc "Bairrche" the 17th King of Ulaid, *96.Blathmac the 14th King of Ulaid, *95.Mael "Cobo" the 13th King of Ulaid, *94.Fiachnae the 10th King of Ulaid, *93.Demman the 6th King of Ulaid, *92.Cyril / Cairell the 3rd King of Ulaid, *91.Murray / Muiredach the 1st King of Ulaid, *90.Forgg mac Dallain.

O Donnan - Irish / Ua Donnain. A Sept / Family branch, who had their territory in Co. Down in the south - east of the Ulster Province. Often confused with O Doonan.

O Donnegan - Irish / Ua Dhonnagain. A Sept / Family branch, who had their territory in Co. Fermanagh in the south - west of the Ulster Province and were Chiefs in Co. Tyrone in Central Southern Ulster and Co. Armagh in the south - east of Ulster.

O Donnegan - Irish / Ua Dhonnagain. A Sept / Family branch, who had their territory in Co. Tipperary in the north - east of Ormond / Aur Mhumhain / North Eastern Munster where they were Princes and kinsmen to the O Gleeson / O Glissane there.

                                                                                  +On to O and Mac Donnell