BoyleIrish From Irish Ó Baoighill meaning "descendant of Baoigheall". The meaning of the given name Baoigheall is uncertain, but it is thought to be connected to Irish geall meaning "pledge".
BradenIrish Anglicized form of Irish Ó Bradáin meaning "descendant of Bradán".
BradyIrish Anglicized form of the Irish name Ó Brádaigh meaning "descendant of Brádach".
CodyIrish Anglicized form of Irish Ó Cuidighthigh meaning "descendant of Cuidightheach". A famous bearer was the American frontiersman and showman Buffalo Bill Cody (1846-1917).
DevlinIrish Anglicized form of the Irish Ó Doibhilin meaning "descendant of Doibhilin", a given name that may be derived from the Gaelic term dobhail meaning "unlucky".
DohertyIrish From the Irish Ó Dochartaigh meaning "descendant of Dochartach". The byname Dochartach means "obstructive".
DonnellyIrish From Irish Ó Donnghaile meaning "descendant of Donnghal". The given name Donnghal means "brown valour", from donn "brown" and gal "valour". This surname is associated with the descendants of Niall of the Nine Hostages.
DouglasScottish Anglicized form of Gaelic Dubhghlas, which meant "dark river" from dubh "dark" and glais "water, river" (an archaic word related to glas "grey, green"). This is the name of various places in Scotland, such as a tributary of the River Clyde.
DoyleIrish From the Irish Ó Dubhghaill, which means "descendant of Dubhghall". A famous bearer was Sir Arthur Conan Doyle (1859-1930), the author of the Sherlock Holmes mystery stories.
DriscollIrish From Irish Ó hEidirsceóil meaning "descendant of the messenger".
Duffy 1Irish Derived from Irish Ó Dubhthaigh meaning "descendant of Dubhthach". Their original homeland was Monaghan where the surname is still the most common; they are also from Donegal and Roscommon.
FannonIrish From the Irish Ó Fionnáin meaning "descendant of Fionn".
FarrellIrish Anglicized form of Irish Ó Fearghail meaning "descendant of Fearghal".
FinneganIrish Anglicized form of Irish Ó Fionnagáin meaning "descendant of Fionnagán". The given name Fionnagán is a diminutive of Fionn.
FlanaganIrish From Irish Ó Flannagáin meaning "descendant of Flannagán". Flannagán is a given name meaning "red". From County Roscommon in Ireland, it has many other spellings.
KavanaghIrish Derived from the Irish Gaelic name Caomhánach, which means "a student of saint Caomhán". It was the name used by a 12th-century king of Leinster, Domhnall Caomhánach, the eldest son of the historic Irish king Diarmait Mac Murchada.
KennedyIrish From the Irish name Ó Cinnéidigh meaning "descendant of Cennétig". This surname was borne by assassinated American president John F. Kennedy (1917-1963).
LennonIrish Anglicized form of the Irish name Ó Leannáin, which means "descendant of Leannán". The given name Leannán means "lover". The name was borne by the musician John Lennon (1940-1980).
MacGregorScottish Anglicized form of Gaelic Mac Griogair meaning "son of Gregor". It originates from the Highland clan Gregor. A famous bearer was the Scottish folk hero Rob Roy MacGregor (1671-1734).
MacKenzieScottish Anglicized form of the Gaelic Mac Coinnich meaning "son of Coinneach". It originates from the Kintail area of Scotland on the northwest coast.
McKinleyScottish Anglicized form of the Gaelic Mac Fhionnlaigh meaning "son of Fionnlagh". This name was borne by the American president William McKinley (1843-1901), who was assassinated.
MonahanIrish From Irish Ó Manacháin meaning "descendant of Manacháin". The given name Manacháin meant "little monk", from manach "monk" and a diminutive suffix.
Monday 3Irish Anglicized form of Mac Giolla Eoin. The last part of the surname was mistakenly taken as the Gaelic word for "Monday", Luain.
MoriartyIrish From Irish Ó Muircheartach meaning "descendant of Muirchertach". This was the surname given by Sir Arthur Conan Doyle to a master criminal in the Sherlock Holmes series.