O'Brien is a common surname of Irish origin.The name is Gaelic, and its original language version is Ua Briain or Ó Briain (pronounced: Ew-Breen/Oh-Breen), meaning 'descendant of Brian'. It carries the sense ‘eminence’, i.e. ‘exalted one’. The Brian referred to is in most cases the ancient Irish king
Brian Boru, or in Gaeilge - Brian Bórumha mac Cennétig.
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