| Name (1649 results) | Rank | Regiment |
|---|---|---|
| Nunn, John | Major | Royal Field Artillery |
| O’Brien, Hugh Conor Henry | Captain | Royal Munster Fusiliers |
| O’Donel, George O’D. F. Thomas | Captain | 4th Battalion Royal Fusiliers |
| Oakes, H.K. | Captain | Canadian Rifles |
| Oakshott, Albert Neville | Lieutenant | Royal Munster Fusiliers |
| O'Brien, Eoghan | Colonel | Royal Engineers |
| O'Brien, James Francis | Lieutenant | Royal Munster Fusiliers |
| O'Brien, Hugh Conor Henry | Captain | Royal Munster Fusiliers |
| O'Brien, Thomas Kevin | Captain | 6th Batt. Connaught Rangers |
| O'Callaghan, James | Lieutenant | 13th Cheshire Regiment |