Brennan (surname)

Brennan is an Irish surname which is an Anglicised form of two different Irish language surnames—Ó Braonáin and Ó Branáin. It can also be found as McBrennan Historically, one source of the surname was the prominent clan Ua Braonáin (O'Brennan) of Uí Duach (Idough) in Osraige who were a junior Dál Birn sept stemming from a younger son of Cerball mac Dúnlainge (d.888). Recent surname evaluations highlighted the geographic consistency of this lineage in the barony of Idough.
The Irish surname "Ó Braonáin", means "descendant of "Braonán"". The personal name "Braonán" is derived from a word which means "moisture", "drop". The Irish surname "Ó Branáin", means "descendant of "Branán"". The personal name "Branán" means "little raven". "Brennan" is also a given name.
Notable people with the surname include: