Breandán Ó Buachalla (1936 – 20 May 2010) was an Irish scholar of the Irish language. According to Raidió Teilifís Éireann, he was "the leading authority on Gaelic poetry and writing in early modern Ireland" and "one of the most prominent Irish language academics of his generation". The Irish Times described him as "eminent". His magnum opus was his seventeenth century literary and political study, Aisling Ghéar. Among his other works are I mBéal Feirste Cois Cuain, Peadar Ó Doirnín: amhráin, Nua-Dhuanaire II, Cathal Buí: amhráin, and Na Stíobhartaigh agus an tAos Léinn: King Seamas.