Brian Ó Cuív was a Celtic scholar who specialised in Irish history and philology.
Ó Cuív was professor of Celtic Studies at University College Dublin and later at the Dublin Institute for Advanced Studies. His later years were devoted to the compilation of a catalogue of the Irish manuscripts in the University of Oxford. The completed catalogue was published after his death.
He married Emer de Valera - who would become the last surviving daughter of Éamon de Valera - with whom he had nine children.