| Regimental number | 4798 |
| Religion | Roman Catholic |
| Occupation | Clerk |
| Address | 28 St John Street, Lewisham, New South Wales |
| Marital status | Single |
| Age at embarkation | 24 |
| Next of kin | Father, J O'Sullivan, 28 St John Street, Lewisham, New South Wales |
| Enlistment date | 20 December 1915 |
| Date of enlistment from Nominal Roll | 29 November 1915 |
| Rank on enlistment | Private |
| Unit name | 20th Battalion, 12th Reinforcement |
| AWM Embarkation Roll number | 23/37/2 |
| Embarkation details | Unit embarked from Sydney, New South Wales, on board HMAT A40 Ceramic on 13 April 1916 |
| Rank from Nominal Roll | Private |
| Unit from Nominal Roll | 20th Battalion |
| Fate | Returned to Australia 25 November 1917 |
| Miscellaneous details (Nominal Roll) | *Spelt James Dennis O'Sullivan on NR |
