| Regimental number | 1364 |
| Religion | Roman Catholic |
| Occupation | Hewer |
| Address | Upper Lansdowne via Taree, New South Wales |
| Marital status | Single |
| Age at embarkation | 47 |
| Next of kin | Brother, James Henry O'Brien, Upper Lansdowne via Taree, New South Wales |
| Enlistment date | 28 September 1915 |
| Rank on enlistment | TPR |
| Unit name | Australian Remount Unit 2, Squadron 5 |
| AWM Embarkation Roll number | 28/3/2 |
| Embarkation details | Unit embarked from Sydney, New South Wales, on board HMAT A67 Orsova on 10 November 1915 |
| Rank from Nominal Roll | Private |
| Unit from Nominal Roll | 2nd Remount Unit |
| Fate | Returned to Australia 24 June 1916 |