A Letter from Ireland:

Where do Irish Surnames come from?


SURNAMES IN GAELIC SCRIPT 7Do you ever wonder – where do Irish Surnames come from? How about YOUR Irish Surname?

Today, we’re going to browse the evolution of the surname in Ireland – something I know is close to your heart! Soon we’ll look at Viking, Norman and Planter names – but for now we start with the old Gaelic names.

First up:

The name is McGee – and don’t call me Bobby!
I got an email from Mary McGee – she asked: “I met a lady called McCoy last year – she insisted we are distant cousins – how could that be?”

Looking through our reader list – I notice that we have Keyes, MacHugh, Gee, McGee, O’Hea, Hayes, MacKaw, Makay and McCoy. What do you think ALL of these surnames have in common? These surnames have all been anglicized from the same Irish surname – “Mac Aodha” (son of Aodh) or “O hAodha” (descendent of Aodh).

Aodh (pronounced “Aay” – rhymes with “hay”) was a very popular first name in Ireland up to the 10th century.

Up to that point individuals were known by their first names and lineage. So, individuals were known as “Aodh son of Donnchadh” and so on.

And then from the 900s to 1100s – families adopted the surname system we know today. Lots of familes across Ireland (and Scotland) chose the name MacAodha or O hAodha – and that got anglicized into the different surnames we see above over the next few centuries.

So, Mary – I guess we’re all cousins going back to Adam and Eve – but this lady is unlikely to be yours!


The First Surnames.
Next, June MacCarthy got in touch –  she asked “why do YOU write MacCarthy as McCarthy?”

Ireland was one of the first countries in Europe to introduce a surname system in the 10th century.

Most Gaelic surnames were formed around an illustrious ancestor e.g. the O’Briens from Brian Boru.  Gaelic surnames typically have one of five prefixes:

  1. “O” as in O’Brien or O’Neill.
  2. Mc or Mac – as in McCarthy or McCoy.
  3. Gil – which comes from the Irish “Giolla” meaning follower – as in Gilmartin.
  4. Mul – like in Mulrooney or Mullarkey.
  5. Sometimes a combination of the above as in Mac Giolla Iosa (MacAleese).

A smaller class of Irish surname named the family after an occupation or profession e.g. McInerney ( Mac an Airchinnigh in Irish) which means “son of the eranagh (a type of accountant)” OR Hickey (in Irish O hIcidhe) which means from the Doctor or Healer.

June wondered about the difference between a Mc and a Mac – some people ask is the Mc Irish and the Mac Scottish? The answer is: there is no difference! They are abbreviations.

Losing the Os and Macs – and getting them back.
Mary Sullivan contacted me – she mentioned “it’s a pity our family lost the “O” when we came to the States.”

But, there’s a bit more to it than that. From the 1600s on – Gaelic and Catholic people were discriminated against by the English ascendency – and this led, gradually, to the abandonment of the Os and Macs in many surnames. O’Murphy became Murphy, O’Kelly became Kelly and so on.

However, in the late 19th century there was a Gaelic cultural resurgence in Ireland and many of these surnames took their Os and Macs back as a badge of Gaelic pride.

Take “O’Sullivan” as an example – when we look at the census data the following comes up:

Year:               Percentage using the prefix O
1866               4%
1890               13%
1914               20%
1944               60%

So, you can see that many emigrants who left Ireland during famine times were missing their Os and Macs – and mostly never took them back. Whereas a high percentage of those who stayed in Ireland had them reinstated.

Maybe its time to take your O or Mac back?

Mary is going to stick with “Sullivan” for now!

That’s it for this week – our rundown on Irish Surnames. Next we will cover other Irish surnames including Norman, Viking and planter names and families.


  • Elaine LOVETT says:

    I submitted my Surname and I am afraid you forgot me??!
    Best regards,Elaine LOVETT

  • nary narrinin says:

    I would like to the know the origin of my name

  • Mary Smith says:

    I have several surnames in my genealogy. (Sullivan, Fitzgerald, Foley, Morrow, Mackle, McDonnell/McDonald) Although I don’t understand the change of the McDonnell to McDonald at all, it’s my Loughran name I’m interested in. It’s somewhat uncommon I think. Mine were from County Tyrone but I’m not sure of the area and they married Mackle (Antrim?) Just curious. Thanks for all your great info you provide.

  • Teresa Carter says:

    My mother’s maiden name was Bailey; my father’s last name was McElvain, I believe that the spelling was changed from McElwain to McElvain by my grandfather. I was wondering what counties in Ireland they might have originated from and perhaps the meanings of their names. Thank you.

    • Mike says:

      Hi Teresa – Bailey would be an English planter name that is really quite spread over Ireland (except Connaught).McElwain – when from Ulster – is usually a version of the Scottish name MacIllvaine. There are also lots of Mac Giolla Bháin (in Irish – it means follower of white – or the white one) in Sligo but thats usually translated to Kinbane in English. Mike.

  • MaryBeth Charley says:

    I submitted the name Charley. I am told we came from County Roscommon. John Charley married Kate (Kathryn?) Mulloly. It is believed they came to America around 1840-50. I have tried Ancestry.com, but did not get very far. Can you help? I visited Ireland in 2011, but with the beauty of the land, and travel, found that there was not enough time to do much research. Thank you so much.

    • Mike says:

      You’ve got me stumped there Marybeth – Charley is originally a Norman name when it came to England first. BUT your version – From Roscommon – I’m suspicious it has a link to a couple of Roscommon names: Mac Searraigh (MacSharry) and Ó Searcóid (Sharkett) – you see there are quite a few names in Roscommon starting with “Sear” which is the “Shar” sound in English. Just a hunch – but I cant tell for sure. Mike.

  • Robert Bruce Irwin says:

    i keep trying to receive you free newsletter but it wont take my name or e-mail address

    • Mike says:

      Hi Robert – I did check the list and you are on it – the email is going out to you each week. So – can you check your spam filters etc. and see if they might be stopping things? Let me know what you find – Mike.

  • Elizabeth Jones says:

    A couple of weeks ago your email asked for surnames that we wanted to know about. You said you would send an email confirming that you had received the request. I’ve been waiting. Since I haven’t received an email, I think my answer to your email must have gotten lost. So, here goes again. My great great grandmother was Mary Ann MORLEY from County Mayo (b.1838). I’ve been told that MORLEY is the English version of an Irish surname. However, when I was in Mayo a couple of years ago, I met a charming fellow in a cemetery that told me Morley is originally a Sussex name. I’d really like to know whether there is an Irish name that MORLEY came from. Please and thank you.

    • Mike says:

      Hi Elizabeth – you’ve got me there – it did indeed fall between the cracks. Thanks for catching up.

      All of your info is right. Morley is an English name assumed by many of the holders of the Irish name “Ó Murghaile”. It is also sometimes anglicised as Morrally. It is from county Mayo originally.

      Hope this helps – Mike.

      • Elizabeth Jones says:

        Mike, Thanks for your response. When you finalize your list of Mayo names for the book, if you haven’t already, would you/ could you please include O’Murghaile or its variants Morley and Morrally? Thank you. Elizabeth

  • Jean Condon says:

    We recieved our t-shirts ( the ones with the crown ) and love them. Hubby and I ordered matching green shirts. We plan to debut them at the family Thanksgiving dinner, hope you have more. They will all be green with envy.

    • Mike says:

      Hi Jean – delighted to hear and thanks for your support! I hope you enjoy the great “unveiling” on Thanksgiving! Mike.

  • mary beattie says:

    My mothers maiden name was McAndrew and my fathers name was Franey.
    Would love to know the origin of both names.
    Thank you.

    • Mike says:

      Hi Mary

      McAndrew in Ireland was a Gaelic surname assummed by a branch of the Norman family the Barretts in Mayo/cork.

      Franey is probably a version of Frain/Frayne/Freeney – all from an original norman family the de Fraynes. (can be Kilkenny/Waterford/Mayo).


  • Mary Margaret Farragher Wieczorek says:

    My surname is Farragher from Co Mayo, maternal name Dolan from Co Galway, I am interested in finding out more about where we came from. love your newsletters thank you very much

    • Mike says:

      Thanks for the vote of confidence Mary Margaret.

      Farragher – is from the Irish Ó Fearchair – and is usually spelled Farraher in Mayo/Galway.
      Dolan – from the Irish Ó Dúbhláin – this is an interesting one. Originally Galway/Roscommon. Mike.

  • Ida Madison says:

    My mother’s maiden name was Ewart. Her line is traced back to Pennsylvania just after the Revolutionary War. However, in two later records her ancestor is listed has having been born in Ireland and coming over as an infant. I believe they came from Northern Ireland, but I don’t know where. Do you have any information on that name?

    • Mike says:

      Hi Ida – Ewart is originally an Scottish and north English name – so in Ulster would have been a planter name. 🙂 MIke.

  • Madilyn says:

    Hi Mike and Carina. Very interesting that some Irish surnames were derived from occupations. I learned from you a while back that my Irish great-grandmother’s surname Mannix is derived from O’Mainchin, meaning Monk. Does that mean the Mannix/O’Mainchin were a tribe of primarily monks? Of course, they could not have all been monks or we never would have gotten very far lol! Is Mannix or O’Mainchin Gaelic? How would a name go from O’Mainchin to Mannix with that “x” on the end? Because I had been away, I was late in replying to your newsletter about surname questions. I hope you received my email with the questions and my little story with what I knew about Bridget Mannix. Thanks!

    • Mike says:

      Hi Madilyn – probably not a tribe of monks. Their progenator may have been a monk or had the demeanour of a monk! We don’t really know. Hard to know where the x came from – certainly an English speaking tongue. There is a Mannix shop in Cork with a couple of auld fellas running it – next time I’m in town I might nip in and ask if they know! All the best, Mike.

      • Madilyn says:

        Thanks so much, Mike! I appreciate that. An aunt in Rhode Island thought our Mannix might have come from Limerick but now I think it may have been Cork instead. All your information is very helpful!

        • Mike says:

          You’re welcome – Mannix is not that prevalent in Cork – but it is there in numbers. And it was originally one of the families of the Corca Laoidhe (south west Cork) – one of the tribes of Ireland we’ll be covering in our forthcoming book! Also – I was thinking about the pronunciation of Mannix – and it is from Manach (said phonetically as “Man-oick”) and if someone was to hear an S at the end of that – it would be “Manachs” OR “Mannix”. Only a theory – Mike.

  • Toni Hamlin says:

    Ya! Love reading your stuff! I’m 2nd generation Irish. My grandmother Madaline McGowan came to Boston from Cork. So I think its even more awsome your writing from cork. Keep up the great writing!

  • Joan Hutchins says:

    Hi Mike. I’m learning so much info abt Ireland & Irish names from you. For xmas Id like some cards w/the name Deir from Tipp. Gonna check out ur store now & see whatchur abt. Also am forwarding this 2 my daughters in Chicago. Ty again 4 info 🙂

    • Mike says:

      Hi Joan – I’m afraid that we will no longer be doing picture products – only the tee shirts for now! Thanks for the request and all your support. All the best, Mike.

  • Kate says:

    Why is Muldoon not in the surnames??

    • Mike says:

      Hi Kate – do you mean on this site? I only work names into the site as people ask questions – thats the reason. And now you’ve asked (so it should now appear in the search box). The name Muldoon comes from the Irish Ó Maoldúin – which comes from 3 different family groupings: one in Fermanagh, one in Clare and the other in Galway. Mike.

  • dale heenan says:

    were does hennan or henin come from?

    • Mike says:

      Hi Dale – Heenan is from the Irish Ó hÉanáin and is usually from the Rosscrea area of County Tipperary – but can also be from County Down. All the best, Mike.

  • DOLORES HOST says:

    I love everything you send.I now have some knowledge of Ireland.I was 3 yrs old when my mom died and I have only searched for my Irish roots a couple of years ago.You can not imagine the joy you have brought.Respecfully Dolores Hanvey Host

  • DOLORES HOST says:


  • Colleen says:

    Curious to know about these Irish surnames:
    Thanks for your webpage. It’s very informative & interesting.

    • Mike says:

      O’Brien – are you joking me, you don’t know about the O’Briens? 😉 Time to try Google!

      All the best – Mike.

  • We have the name Collins in my family. The family debates wether it is Irish or English. Unfortunately, while trying to trace the family line, we cannot get the line back over to that side of the pond (yet).

  • CAROL HULTS says:

    My maiden name is Curran. I am planning a trip to Ireland this summer I would like to know where to visit to find out about the Curran’s.

    • Mike says:

      Hi Carol – this one will have you travelling. Curran comes from a number of distinct families in County Waterford/Tipperary (this is the main family), Galway/Leitrim, Donegal and Kerry. All the best – Mike.

  • Sarah Kidder says:

    My maiden name is McIlveen and my Gaelic professor in university told me it translated to Mhic Giolla Mhin. Grandparents were from Belfast. Can’t find ANYTHING about my grandfather’s side besides my g.grandparent’s names and very little about my grandmother’s except her maiden name was Margaret Houston, her mother was Margaret Honer and HER mother was Magrit Carlsson. Which in not Irish!

    • Mike says:

      Sounds like a real set of puzzles there Sarah! Mac Giolla Mhín is indeed from County Down and means “son/daughter of the follower of the gentle one”. Mike.

  • Claire McGrievy Finley says:

    Dear Mike, any information on where the McGrievy’s came from . My great grandparents left Ireland before 1903 and went to England. On the English paperwork they only put down Irish Free State as their place of birth . Thank you , Claire

    • Mike says:

      Hi Claire – McGrievy (usually spelled McGreevy) is from the Irish Mag Riabhaigh and is typically found around County Roscommon. All the best, Mike.

  • Barb Morin says:

    Hi. I can’t tell if you are still following up Irish surnames… My GGrandmother was a FLYNN. Her Parents FLYNN and CARBERRY, married in county Roscommon, but kids baptized county Sligo. I have literally hundreds of Michael Flynn, but find no Carberry in Roscommon or Sligo, so my genealogy hit the wall.

  • Doris Byrne says:

    Hi Mike, My Great grand father came from Ireland, His name was Thomas Killilea, ,parents Michael and Margaret . Thomas was born around 1830’s. Where did he come from? Came to America in 1866?

  • Seán R. Mac Aodha says:

    I’m happy to report, my “Mac” is fully intact. 😉

  • Michele Rooney-Hodelin says:

    You are incredibly awesome in your knowledge base and the many benefits and education you provide to all of us through your hard work and dedication! I thank you tremendously.

  • Linda Mangan says:

    I check out all the Irish surnames but haven’t seen Mangan. My Great Great Grandfather Jeremiah Dermot (Darby) Mangan was born in County Roscommon, but I haven’t found where the name came fround. Where would I look?

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