| Regimental number | 2444 |
| Religion | Roman Catholic |
| Occupation | Billiard marker |
| Address | Myall Street, Dubbo, New South Wales |
| Marital status | Single |
| Age at embarkation | 29 |
| Next of kin | Mother, Mrs M A O'Brien, Myall Street, Dubbo, New South Wales |
| Enlistment date | 22 July 1915 |
| Rank on enlistment | Private |
| Unit name | 18th Battalion, 5th Reinforcement |
| AWM Embarkation Roll number | 23/35/2 |
| Embarkation details | Unit embarked from Sydney, New South Wales, on board HMAT A32 Themistocles on 5 October 1915 |
| Rank from Nominal Roll | Private |
| Unit from Nominal Roll | 2nd Machine Gun Battalion |
| Fate | Returned to Australia 27 April 1919 |
| Miscellaneous details (Nominal Roll) | *Spelt James Dennis O'Brien on NR |
