| Regimental number | 5085 |
| Place of birth | Gordon, Ballarat, Victoria |
| School | St Patrick's (Catholic) College, Ballarat, and Teacher's Training College, Melbourne, Victoria. |
| Religion | Roman Catholic |
| Occupation | Soldier |
| Address | Gordon, Victoria |
| Marital status | Single |
| Age at embarkation | 23 |
| Next of kin | Father, C O'Brien, Gordon, Victoria |
| Previous military service | Served as a Lieutenant in the Citizen Military Forces. |
| Enlistment date | |
| Rank on enlistment | Sergeant |
| Unit name | 29th Battalion, 14th Reinforcement |
| AWM Embarkation Roll number | 23/46/4 |
| Embarkation details | Unit embarked from Melbourne, Victoria, on board HMAT A38 Ulysses on |
| Rank from Nominal Roll | Sergeant |
| Unit from Nominal Roll | 29th Battalion |
| Fate | Killed in Action |
| Age at death | 24 |
| Age at death from cemetery records | 24 |
| Place of burial | Serre Road Cemetery No. 2 (Plot XXIV, Row C, Grave No. 2), France |
| Panel number, Roll of Honour, Australian War Memorial | 116 |
| Miscellaneous information from cemetery records | Parents: Cornelius and Annie O'BRIEN, Gordon |
| 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
