 | O'Brian, Peter Geoffrey St. George | 17-12-1917 | 15-04-2007 |  |
 | O'Brien, Joseph Somerton | 09-04-1912 | 07-09-1940 |  |
 | O'connor, Maurice | | | |
| O'Donnell, E. | | | |
| O'Driscoll, Finan | 18-07-1916 | 16-01-1942 |      |
| O'Leary, Arthur Alexander | 04-01-1921 | 21-04-1987 |  |
 | O'Meara, James Joseph | 20-02-1919 | 04-06-1974 |   |
| O'Neil-Shaw, Denzil Philip Liddell | 00-00-1910 | 00-00-1968 |  |
 | O'Neill, Eugene Hugh "Mick" | 00-09-1913 | |   |
| O'Neill, Hugh Francis 'Peggy' | 00-00-1920 | |   more |
| Oakes, Eric Raymond | | | |
| Oakeshott, Geoffrey Jonathan | 20-04-1922 | | |
| Ocelka, Josef | 12-03-1909 | 21-07-1942 |     more |
| Odell, Edward Nelson | | | |
 | Offenberg, Jean Henri Marie "Pyker" | 03-07-1916 | 22-01-1942 |  |
| Ogilvie, Alfred Keith | 14-12-1915 | 26-05-0199 | |
 | Ogilvie, Allan Macpherson (Joe) | 07-03-1921 | 30-12-2000 |   more |
| Ogilvie, Donald Gordon | 03-11-1916 | 13-06-1943 | |
| Ogilvie, Patrick Bruce Bine | 14-01-1910 | 11-12-1944 | |
| Ogrodnik, Tadeusz | 11-11-1917 | 27-08-1944 |  |
| Oliver, George William RAF | | |  |
| Olszewski, Ignacy | 13-07-1913 | 16-09-2004 |    more |
 | Olver, Peter | | | |
 | Omylak, Franciszek Kazimierz | 14-09-1907 | 28-08-1944 | |
 | Orlinski, Boleslaw | 13-04-1899 | 28-02-1992 |        more |
| Orman, Kenneth Gerald | | |  |
 | Orme, Frank Kerr | 12-03-1916 | 28-08-1941 |   |
| Orzechowski, Jan | 05-05-1905 | 27-02-1942 |  |
| Osadzinski, Alfred Zdzislaw | 12-09-1916 | 06-04-1942 | |
 | Osborne, Albert Matthew "Matt" | 19-10-1906 | 02-04-1942 |  |
| Osieleniec, Kazimierz | 31-07-1918 | 21-04-1944 | |
| Osmialowski, Leon Boleslaw | 11-04-1916 | 31-08-1943 | |
| Osuchowski, Zbigniew Zygmunt | 22-01-1909 | 14-10-1944 |  |
| Oswick, John Roger Gunston | 26-11-1921 | 26-08-2016 | |
| Owen, Brian John Francis | 23-08-1922 | 15-10-1992 | |
| Owen, Charles Maxwell | | | |
 | Owen, John David | 11-09-1920 | 25-03-1944 | |
| Owen, John Griffith | | 13-10-1943 | |
 | Oxborrow, John Edgar Percival | 09-01-1922 | 12-09-1944 |  |
| Oxby, Douglas Alfred "Douggie" | 10-06-1920 | 10-04-2009 | more |
| Oxspring, Robert Wardlow "Oxo" | 22-05-1919 | 08-08-1989 |  more |
| Oyrzanowski, Waclaw | 18-09-1903 | 27-06-1943 | |
 | Ozga, Jan Franciszek | 30-08-1919 | 27-08-1944 |  |
| Ozyra, Piotr | 11-05-1912 | 29-04-1942 | |
