| Regimental number | 1504 |
| Religion | Roman Catholic |
| Occupation | Labourer |
| Address | Pipeclay, via Mudgee, New South Wales |
| Marital status | Single |
| Age at embarkation | 22 |
| Next of kin | Father, Michael O'Brien, Pipeclay, via Mudgee, New South Wales |
| Enlistment date | 3 September 1915 |
| Date of enlistment from Nominal Roll | 18 September 1915 |
| Rank on enlistment | Private |
| Unit name | 6th Light Horse Regiment, 11th Reinforcement |
| AWM Embarkation Roll number | 10/11/3 |
| Embarkation details | Unit embarked from Sydney, New South Wales, on board HMAT A14 Euripides on 2 November 1915 |
| Rank from Nominal Roll | Gunner |
| Unit from Nominal Roll | 3rd Field Artillery Brigade |
| Fate | Returned to Australia 24 January 1919 |