 O'Boyle, Patrick, 1896-1987 (1) |
| O'Connell, Denis Joseph, 1849-1927 (1) |
| O'Connell, William Henry, 1859-1944 (1) |
| O'Connor, Martin John, 1900-1986 (1) |
| O’Hara, Edwin V. (Edwin Vincent), 1881-1956 (1) |
| O'Hern, Charles A. (1) |
| O'Mahony, John, 1816- (1) |
| O'Neill, John, 1843-1878 -- Speech (1) |
| Otis, Lucinda Smith (1) |
| Passow, Harry A. (1) |
| Paulsen, Charles (1) |
| Paul V, Pope, 1552-1621 (1) |
| Phipps, Henry, 1839-1930. (1) |
| Pine, Max (1) |
| Pius IX, Pope, 1792-1878 (3) |
| Pius VIII, Pope, 1761-1830 (1) |
| Pius XI, Pope, 1857-1939 (1) |
| Pius X, Pope, 1835-1914 (1) |
| Poinsett, Joel Roberts, 1779-1851 (1) |
| Powderly, Terence Vincent, 1849-1924 (1) |
| Queen, H. W. (Henry W.), d. 1874 (1) |
| Queen, Nicholas Louis (1) |
