| Person # | Last Name | First Name | Initials | Rank | Year |
|---|---|---|---|---|---|
| 5588 | O'brien Despard | William Hugh | W H | Corporal | 1920 |
| 19208 | O'bryen | William Stanislaus | W S | Sub-Lieutenant (A) | 1942 |
| 19210 | O'byrne | Edward | E | Constable | 1941 |
| 19211 | O'callaghan | James | J | Second Lieutenant | 1916 |
| 19213 | O'connell | Daniel | D | Private | 1918 |
| 19214 | O'connell | Douglas Charles | D C | Private | 1917 |
| 19215 | O'connell | Edward Thomas | E T | Private | 1917 |
| 19216 | O'connell | William Joseph Andrew | W J A | Private | 1943 |
| 19219 | O'connor | C G | Gunner | 1942 | |
| 19222 | O'connor | F A | Lieutenant | 1944 | |
| 37040 | O'connor | Albert Cortney Michael | A C M | Plain Clothes Constable | 1922 |
| 19217 | O'connor | Arthur Cathal | A C | Captain | 1916 |
| 19218 | O'connor | Clarence Frederick Reid | C F R | Private | 1916 |
| 19220 | O'connor | Daniel | D | Private | 1917 |
| 19221 | O'connor | Daniel William | D W | Corporal | 1942 |
| 32357 | O'connor | Desmond | D | Lieutenant | 1981 |
| 19223 | O'connor | Gilbert Rademan | G R | Major | 1942 |
| 19224 | O'connor | James | J | Private | 1917 |
| 19226 | O'connor | James Mathew | J M | Lance Corporal | 1920 |
| 19225 | O'connor | John | J | Private | 1916 |
| 19227 | O'connor | Robert Emmet | R E | Private | 1918 |
| 19228 | O'connor | Robert John | R J | Flight Sergeant | 1943 |
| 19229 | O'connor | Stephen James | S J | Private | 1916 |
| 32356 | O'connor | Walter Donald | W D | Rifleman | 1979 |
| 19239 | O'cully | Patrick | P | Private | 1918 |
| 19240 | O'daly | Charles Nicholas Frederick | C N F | Dresser | 1917 |
| 19242 | O'dea | Daniel | D | Corporal | 1943 |
| 19243 | O'dea | John | J | Corporal | 1917 |
| 19244 | O'dea | Peter | P | Private | 1916 |
| 19245 | O'dea | Peter Andrew | P A | Corporal | 1944 |
| 19246 | O'dell | D F | Private | 1947 | |
| 19253 | O'donnell | James | J | Private | 1918 |
| 19254 | O'donnell | Patrick Rhodes | P R | Warrant Officer Class II | 1942 |
| 19255 | O'donoghue | James Michael | J M | Corporal | 1942 |
| 19256 | O'donoghue | James Patrick | J P | Trooper | 1944 |
| 19257 | O'donoghue | Patrick Roderick | P R | Private | 1916 |
| 19258 | O'donoghue | Philip Stephen | P S | Sergeant | 1917 |
| 40150 | O'donovan | John Finbarr Gerard | J F G | Patrol Officer | 1972 |
| 40151 | O'driscoll | Gary Arthur | G A | Corporal | 1977 |
| 19270 | O'farrell | Maurice | M | Driver | 1915 |
| 32365 | O'gorman | Brian Alphonso | B A | Airman | 1965 |
| 19280 | O'gorman | Cyril John | C J | Lance Corporal | 1918 |
| 19282 | O'halloran | John Patrick | J P | Sergeant Major | 1917 |
| 19283 | O'hanlon | Richard | R | Corporal | 1916 |
| 19284 | O'hara | James Bernard | J B | Staff Sergeant | 1921 |
| 19287 | O'keefe | Terence Desmond | T D | Warrant Officer Class I | 1944 |
| 19288 | O'kelly | Thomas | T | Private | 1918 |
| 19289 | O'kennedy | John Morgan | J M | Private | 1918 |
| 19304 | O'leary | Kevin Leahy | K L | Captain | 1945 |
| 19378 | O'meara | Bulkeley Ernest Adolphus | B E A | Captain | 1916 |