 On December 6, 1982, Pope John Paul II appointed O'Donnell auxiliary bishop of the Saint Louis Archdiocese, and he was consecrated as bishop on February 10, 1983.On November 8, 1994, Pope John Paul II appointed Bishop O'Donnell Bishop of the Lafayette Diocese in Louisiana.Bishop O'Donnell retired on November 8, 2002 and died in Saint Louis, aged 77.