Career
O'Shea was appointed the Vicar Apostolic of Heijo and Titular Bishop of Naissus on 11 July 1939. He was consecrated by Pope Pius XII on 29 October 1939, with archbishops Celso Benigno Luigi Costantini and Henri Streicher serving as co-consecrators. O'Shea died in office on 22 February 1945, aged 60.