O Muldorry or O Mulderry - Irish / Ua Maoldoraidh - maeldoraig. A  Heremonian Ui Cobhthaigh Dal Cuinn "Northern" Ui Niaill Cenel Conaill Sept / Family branch who were Princes in the kingdom in Tir Conaill / Tyrconnell (The Land of *88.Conall) in their territory in Co. Donegal in the north - west of the Ulster Province. Ancestors - *88.Conall "Gulban" the 1st King of Tir Conaill / Tyrconnell (Cenel Conaill), *87.Niall of the Nine Hostages the 126th King of Tara / Ireland (Ui Niaill). See also - Mac Ilinions.

O Muldowneys or O Downeys. A Heberian Dal gCais Ui Bloid Sept / Family branch, who had their original territory in Thomond / Northern Munster descended from *93.Brennan / Breanainn "Bran" the direct ancestor of the Muinter Urthaile, the Muinter Maol Domhnaigh and the Muinter Chearnaigh, which were all to also produce the Families of the O Brennans, O Glinn / O Glynn, O Hurleys, O Maglins, O Maegans and O Maloneys. Ancestors - *93.Brendan / Breanainn "Bran," *92.Blood / Blod (Ui Bloid), *91.Cas (Dal gCais) the King of Thomond.

O Muldowney - Irish / Ua Maoldhomhnaigh. A Sept / Family branch, who had their territory in Co. Kilkenny in the south - west of Southern Leinster.

O Muldowney - Irish / Ua Maoldomhnaigh. A Sept / Family branch, who had their territory in the Ulster Province. O Downey, O Gildowney, Mac Downey, Mac Goldowney and Muldowney are used there synonymously in the Newry region.

O Mulfall  or O Mulfaal - Irish / Ua Mael Fhabhaill. A Sept / Family branch, who had their territory originally in the north of the Connacht Province but were also in Co. Donegal in the north - east of the Ulster Province. See also - Lavelle.

O Mulfoyle - Irish / Ua Mael Fhabaill - A Heremonian Ui Cobhthaigh Dal Cuinn "Northern" Ui Niaill Cenel nEogain Cenel Fergus Sept / Family branch, who had their territory at Upper Dungannon in Co. Tyrone in the Ulster Province. Ancestors - *89.Fergus, *88.Eogan the 1st King of Aileach (Cenel nEogain), *87.Niall of the Nine Hostages the 126th King of Tara / Ireland (Ui Niaill).

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

O Mulhall or O Mulcahill - Irish / Ua Maolchathail (Descended from a devotee of St. Cathal) A Sept / Family branch, who had their territory in Co. Laois in the mid - north - west of Southern  Leinster. See also Halley.

O Mulholland - Irish / Ua Maolchalann (Descended from a  devotee of St. Calann) A Heberian Eoghanacht Ui Fidgeinte Sept / Family branch, who had their territory in the north of Co. Limerick in Ormond / Aur Mhumhain / North Eastern Munster. Ancestors -*88.Maine "Munchain" whose son was *89.Fiachu "Fidgennid " the father of *90.Brion the actual direct ancestor of the two Ui Fidgeinte Septs, *85.Eoghan "Mor" (Eoghanachta), *84.Ailill "Oluimm" the 1st King of Munster.

O Mulkerrin or O Mulkieran - Irish / Ua Maoilchiarain (Descended from a devotee of St. Kieran / Ciaran) A Heremonian Ui Cobhthaigh Dal Cuinn Ui Fiachrach Erenagh Sept / Family branch, who had their territory at Ardcane in Co. Roscommon in the east of the Connacht Province who produced many notable ecclesiastics also in the Ulster Province. In Co. Galway in Southern Connacht O Mulkerrin is now also used for O Mulkerrill, which see. Ancestors - *87.Fiachra the original 2nd King of Connacht (Ui Fiachrach), *86.Eochy "Mugmedon" the 124th King of Tara / Ireland.

Mac Mulkin - Irish / Mheic Maolchaoin. Used in Co. Tyrone in Central Ulster and nearby in Co. Fermanagh in the south - west of Ulster and Co. Mayo in the mid - west of the Connacht Province. See also - Mulqueen.

O Mulooley -  Irish / Mheic Mioluc (Descended from Milo). An Irian Conmaicne Rein Muinter Eolais Tellach Cearbhallan Sept / Family branch, who had their territory at Mohill and Leitrim in Co. Leitrim in Northern Connacht. Especially see - O Mulhooly.

O Mullally or O Lally - Irish / Ua Maolalaidh - aladh / speckled. A Heremonian Ui Cobhthaigh Dal Cuinn Ui Maine Sept / Family branch, who had their territory in Co. Roscommon in the east of the Connacht Province and were Chiefs and Kings in Co. Galway in Southern Connacht. When known as Lally they were connected to the "Wild Geese" in Spain. 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 Mullan or O Mullins or O Mullen or *O Mullane or O Mellon - Irish / Ua Maolain - maol / bald or tonsured. A Heremonian Ui Cobhthaigh Dal Cuinn Ui Briuin Sept / Family branch, who had their territory in Co. Galway in Southern Connacht. They were descended from *Maolan who was himself descended from a Ui Briuin King of Connacht. Ancestors - *Maolan, *87. Brion the original 1st King of Connacht (Ui Briuin), *86.Eochy "Mugmedon" the 124th King of Tara / Ireland.

O Mullan or O Mullin or O Mullins or O Mullen or O Mullane or O Mollins - Irish / Ua Maolain. A Sept / Family branch, who had their territory in Co. Monaghan in Southern Ulster at Clones.

O Mullan or O Mullane or O Mullins. A Sept / Family branch, who had their territory in the south of Co. Cork in Desmond / Des Mhumhain - Southern Munster. Also known as O Mullane in Co. Waterford in the south - east of Munster. *Chiefs in Co. Kerry in the south - west of Munster were they are frequently known as O Mullins.

O Mullane or O Mullins - Irish / Ua Maolain. A Sept / Family branch of the O Mullan, which see, in Co. Cork in Southern Munster and especially in Co. Clare in the north - west of Munster where O Millane was also used as a variant.

O Mullaney - Irish / Ua Maoileanaigh. A Sept / Family branch, who had their territory in Co. Waterford in the south - east of the Munster Province.