| Regimental number | 3214 |
| Religion | Roman Catholic |
| Occupation | Farmer |
| Address | Hansonville, Victoria |
| Marital status | Single |
| Age at embarkation | 21 |
| Next of kin | Brother, John O'Brien, Hansonville, Victoria |
| Enlistment date | 19 July 1915 |
| Rank on enlistment | Private |
| Unit name | 24th Battalion, 7th Reinforcement |
| AWM Embarkation Roll number | 23/41/2 |
| Embarkation details | Unit embarked from Melbourne, Victoria, on board HMAT A73 Commonwealth on 26 November 1915 |
| Rank from Nominal Roll | Driver |
| Unit from Nominal Roll | 3rd Company, Australian Army Service Corps |
| Fate | Returned to Australia 12 May 1919 |