| Religion | Roman Catholic |
| Occupation | Law clerk |
| Address | 'Villette', 131 Hotham Street, St Kilda, Victoria |
| Marital status | Single |
| Age at embarkation | 27 |
| Next of kin | Father, J G Duffy, 'Villette', 131 Hotham Street, St Kilda, Victoria |
| Enlistment date | 3 April 1916 |
| Rank on enlistment | 2nd Lieutenant |
| Unit name | Field Artillery Brigade 1, Reinforcement 23 |
| AWM Embarkation Roll number | 13/29/4 |
| Embarkation details | Unit embarked from Sydney, New South Wales, on board RMS Orontes on 19 December 1916 |
| Rank from Nominal Roll | Lieutenant |
| Unit from Nominal Roll | 1st Field Artillery Brigade |
| Fate | Returned to Australia 16 June 1919 |
| Miscellaneous details (Nominal Roll) | *Stated to be John Leo Duffy on NR |
