Irish derivation: Ó Briain.

Name meaning: "Descendant of Brian (Boru)."

Counties associated with the name: Cork, Clare, Donegal, Dublin, Fermanagh, Kilkenny, Limerick, Meath, Tipperary, Wexford, and Wicklow.

Coat of arms motto: "The strong hand from above."

Read more: What's your Irish clan?

Interesting Facts:

- Queen Elizabeth II's maternal eigth great grand-mother was an O'Brien. 

- Emerged as chiefs of the Dalcassian races from the south-west of Ireland. 

- Founded by Brian Boru.

Some famous O'Briens:

- Conan O'Brien (b.1963, US comedian and talk show host)

- Soledad O'Brien (b.1966, journalist)

- Mick O'Brien (b.1961, traditional Irish musician)

- Miles O'Brien (b.1959, journalist and CNN anchor)

- Richard O'Brien (b.1942, actor and writer of cult hit 'Rocky Horror Picture Show')

Read more: What's your Irish clan?