Eóin àCuileannáin, S.T.D. (anglicised John O'Cullenan; âÂÂ1661) was an Irish Roman Catholic prelate who served as the Bishop of Raphoe from 1625 to 1661.
àCuileannáin was appointed Vicar Apostolic of the Roman Catholic Diocese of Raphoe by papal brief on . Four years later, he was appointed Bishop of Raphoe on , but was not consecrated until 1629. After having been held in prison in Derry for several years, Bishop àCuileannáin went into exile in March 1653.
Eóin àCuileannáin died in Brussels on 24 March 1661, aged about 78, and was interred in the chapel of the Virgin in the Cathedral of St. Michael and St. Gudula.