Surnames beginning in "Mc" and "Mac"... Irish or Scottish?

[Sikeliot]

I have heard that surnames beginning in "Mc" are Irish and those beginning in "Mac" are Scottish. Is this true?

I have come to believe not, because there are some surnames beginning in "Mc" that I have only ever met Irish people having, like McGrath, McMahon, McEvoy, and McCarthy, and others that I have only ever heard of being Scottish such as McDougall, McGregor, and McKinley.. whereas I have seen "MacCarthy" and "MacMahon" both belonging to Irish people and spelled that way instead.

So which is correct? What is applicable for people you have met?

[Newsboy]

Mc and Mac are Gaelic prefixes most likely used among both Irish and Scottish surnames. Mc is probably the more Anglicized version of Mac. Both of them mean 'son of'. Mc surnames are often further anglicized, i.e McMahon becomes Matthews and McShane becomes Johnson. The O' prefix would be strictly Irish, as O'Neill or O'Gorman for instance.

Scottish and Irish surnames are often very similar because both surnames are of Gaelic origin. I'm not sure, but I think Scottish and Irish Gaelic are almost mutally intelligible.

[Grumpy Cat]

Scottish. Irish use O.

[Sikeliot]

Scottish. Irish use O.

I don't think that's true. A lot of Irish surnames do start in Mc. But you are partially right in "O'" surnames never being Scottish.

[Baluarte]

Both, perhaps Scottish has a somewhat higher incidence.

[Newsboy]

I don't think that's true. A lot of Irish surnames do start in Mc. But you are partially right in "O'" surnames never being Scottish.

True. McManus, McNamara, McGrath, McCarthy, and McGovern are examples of Irish surnames with this prefix. It is not a Scottish prefix but a Gaelic one.

[Sikeliot]

True. McManus, McNamara, McGrath, McCarthy, and McGovern are examples of Irish surnames with this prefix. It is not a Scottish prefix but a Gaelic one.

And any of the ones with "gill" in them are Irish.. McGillis, McGillicuddy, McGill etc. I've never seen any of those as Scottish.

I am just asking whether there is a rule as to which ones are generally Irish or Scottish.. is it a Mc versus Mac rule or is it some names just Irish and others just Scottish. I think it's the latter.

[1stLightHorse]

It's Gaelic, and it means "Son of" for example....Mc Cullagh means 'Son of a Boar'

Mc = Son
Cullagh = Wild Boar


O' means "Descendant of", for example O'Niall means 'Descendant of Niall'.

[Baluarte]

Makes you wonder how they said "Son of a bitch"

[1stLightHorse]

Vince McMahon, in translation, Vince, Son of a Bear. He lives up to this name i believe.