 | O'Brian, Peter Geoffrey St. George | 17-12-1917 | 15-04-2007 |  |
 | O'Connell, George Francis Leo | 08-12-1923 | 22-06-1944 |  |
 | O'Connor, Frances Lenora | 03-04-1917 | 21-12-1993 |    |
 | O'Connor, James | 21-04-1887 | 24-05-1915 |  |
| O'Hara Keating, John Gerald | | 08-09-1941 | |
 | O'Hara, Otis Conwell | 06-11-1916 | 30-03-2005 |     |
| O'Leary, Robert J. | | |  |
| O'Neill, Alphonsus Benedict Joseph | | |  |
 | O'Neill, Daniel | 27-02-1918 | 03-02-1943 | |
| O'Reilly, James Patrick Gallery | 12-12-1920 | 22-06-1943 | |
| O'Reilly, Michael Douglas | 00-00-1922 | | |
 | Odell, James Gilmour | 19-02-1915 | 23-11-1943 |  |
| Oerton, Clarence F. | | | |
| Ogilvie, Alfred Keith | 14-12-1915 | 26-05-0199 | |
 | Ogilvie, Allan Macpherson (Joe) | 07-03-1921 | 30-12-2000 |    more |
| Oldford, Joseph Winston "Joe" | 27-04-1916 | 16-07-2005 |  |
| Ollerenshaw, James W. | | | |
| Olmsted, William Alfred | | |  |
| Olson, Carl Robert | 09-07-1918 | | |
 | Oneson, Paul Patrick Augustus | 03-02-1916 | 30-06-1942 | |
| Orde, Reginald John | 15-05-1893 | 03-06-1975 |     |
| Orlinski, Casimir Frank | 21-08-1923 | 22-06-1943 | |
 | Orme, Frank Kerr | 12-03-1916 | 28-08-1941 |  |
 | Ormiston, William Delbert | | 21-02-1945 | |
 | Orr, James Samuel | | 02-09-1942 | |
| Orr, Robert James | | | |
| Orr, Ross W. | | |  |
 | Osborn, John Robert | 02-01-1899 | 19-12-1941 |   more |
 | Osborne, Leonard Frank | | 07-10-1944 | |
 | Osler, Kenneth Siddons | | 12-06-1944 | |
| Ostir, Frank | 07-02-1919 | 08-06-1944 | |
| Ouderkirk, Orvest Miles | | |  |
| Ouellet, Charles E. | | | |
| Ouellet, Joseph Anthony | | |  |
| Oulton, Blake A. | | | |
| Owchar, William | | | |
 | Owen, John David | 11-09-1920 | 25-03-1944 | |
| Owens, Allan R. | | 08-06-1944 | |
| Ozment, Donald Eric | | 27-12-1941 | |
