| Regimental number | 325 |
| Place of birth | Townsville, Queensland |
| School | Christian Brothers (Catholic) School, Fremantle, Western Australia |
| Religion | Roman Catholic |
| Occupation | Clerk |
| Address | Stuart Street, Cottesloe Beach, Western Australia |
| Marital status | Single |
| Age at embarkation | 20 |
| Next of kin | Father, Mortimer O'Brien, Stuart Street, Cottesloe Beach, Western Australia |
| Previous military service | 87th Infantry; nil. |
| Enlistment date | |
| Date of enlistment from Nominal Roll | |
| Rank on enlistment | Private |
| Unit name | 44th Battalion, B Company |
| AWM Embarkation Roll number | 23/61/1 |
| Embarkation details | Unit embarked from Fremantle, Western Australia, on board HMAT A29 Suevic on |
| Rank from Nominal Roll | Private |
| Unit from Nominal Roll | 44th Battalion |
| Fate | Died of wounds |
| Place of death or wounding | Passchendaele, Belgium (possibly) |
| Age at death | 22.1 |
| Age at death from cemetery records | 22 |
| Place of burial | Bologne Eastern Cemetery (Plot VIII, Row I, Grave No. 77), France |
| Panel number, Roll of Honour, Australian War Memorial | 138 |
| Miscellaneous information from cemetery records | Parents: Mortimer and Sarah O'BRIEN, Stuart Street, Cottesloe Beach, Western Austalia. Native of Townsville, Queensland |
| Other details |
War service: Western Front Medals: British War Medal, Victory Medal |
Postal Address:
Po Box 7916
Canberra BC 2610, Australia
Street Address:
Northcott Drive,
Campbell, ACT 2600
