| Regimental number | 4648 |
| Place of birth | North Melbourne, Victoria |
| School | Christian Brothers College, Melbourne, Victoria |
| Religion | Roman Catholic |
| Occupation | Printer |
| Address | 120 Chetwynd Street, North Melbourne, Victoria |
| Marital status | Single |
| Age at embarkation | 19 |
| Next of kin | Father, J O'Brien, 120 Chetwynd Street, North Melbourne, Victoria |
| Previous military service | Served as a Gunner in the Citizen Military Forces |
| Enlistment date | |
| Date of enlistment from Nominal Roll | |
| Rank on enlistment | Gunner |
| Unit name | Field Artillery Brigade 2, Reinforcement 7 |
| AWM Embarkation Roll number | 13/30/2 |
| Embarkation details | Unit embarked from Melbourne, Victoria, on board HMAT RMS Persia on |
| Rank from Nominal Roll | Gunner |
| Unit from Nominal Roll | 2nd Field Artillery Brigade |
| Fate | Died of disease |
| Place of death or wounding | Heliopolis, Egypt |
| Age at death | 20.6 |
| Age at death from cemetery records | 20 |
| Place of burial | Cairo War Memorial Cemtery (Row M, Grave No. 104), Egypt |
| Panel number, Roll of Honour, Australian War Memorial | 12 |
| Miscellaneous information from cemetery records | Parents: John and Catherine O'BRIEN, 120 Chetwynd Street, North Melbourne, Victoria |