| Regimental number | 21390 |
| Place of birth | Rockhampton Queensland |
| Religion | Roman Catholic |
| Occupation | Storekeeper |
| Address | Capella, Queensland |
| Marital status | Single |
| Age at embarkation | 21 |
| Next of kin | Father, T O'Brien, Capella, Queensland |
| Enlistment date | |
| Rank on enlistment | Gunner |
| Unit name | 9th Field Artillery Brigade, Brigade Ammunition Column |
| AWM Embarkation Roll number | 13/36A/1 |
| Embarkation details | Unit embarked from Sydney, New South Wales, on board HMAT A8 Argyllshire on |
| Rank from Nominal Roll | Gunner |
| Unit from Nominal Roll | 1st Field Artillery Brigade |
| Fate | Returned to Australia |
| Miscellaneous details (Nominal Roll) | *Spelt Thomas Julien O'Brien on NR |
| Miscellaneous information from cemetery records | Plaque in Queensland Garden of Remembrance |
| Date of death |