| Regimental number | 41005 |
| Occupation | Clerk |
| Next of kin | Brother, Martin O'Brien, Richmond Grove, Invercargill |
| Rank on embarkation | Rifleman |
| Unit name | New Zealand Expeditionary Force, New Zealand Rifle Brigade Reinforcements, H Company |
| Embarkation details | Unit embarked from Wellington on board HMNZT Ruapehu on |
| Sources | Nominal Roll Vol. 3: Roll 57, p. 33 |