Seaán Ó hEidhin, Franciscan Bishop of Clonfert, fl. 1437-1459.
Ó hEidhin was a descendant of Eidhean mac Cléireach of the Uí Fiachrach Aidhne dynasty. He was a suffragan bishop, first noted as an attendant of King Henry VI in 1437. A native of Clonfert, he acted as the king’s messenger between the rebellious clergy assembled at Basel who were eager to prove that the Pope was subordinate to the General Council; to the Holy Roman Emperor; Sigismund, Archduke of Austria; and to Pope Eugenius IV.
He never took actual possession of his office, it been taken by Tomás mac Muircheartaigh Ó Cellaigh, son of Bishop Muircheartaigh Ó Cellaigh. At the time of Ó Cellaigh's death in 1441, John White, provincial minister of the Friars Minor was deposed from his position for bad government. He traveled to Rome and was appointed to Ó Cellaigh’s position, which he held till his death in 1447, leaving Ó hEidhin a bishop without a diocese. He worked as a suffragan or auxiliary bishop in Worcester (1443), London, (1443-1448), Exter (1447), and was at the time of his death vicar of West Thurrock, near London.