| Regimental number | 42 |
| Religion | Roman Catholic |
| Occupation | Jeweller |
| Address | 46 Canterbury Road, Middle Park, Melbourne, Victoria |
| Marital status | Single |
| Age at embarkation | 29 |
| Next of kin | Father, Thomas Michael O'Brien, 46 Canterbury Road, Middle Park, Melbourne, Victoria |
| Enlistment date | |
| Rank on enlistment | Private |
| Unit name | Australian Naval & Military Expeditionary Force (Queensland Reinforcement) |
| Miscellaneous details (Nominal Roll) | Name does not appear on Nominal Roll |