| Regimental number | 3295 |
| Religion | Roman Catholic |
| Occupation | Railway porter |
| Address | Lameroo, South Australia |
| Marital status | Single |
| Age at embarkation | 24 |
| Next of kin | Brother, J O'Leary, Donoughnore, Co Cork, Ireland |
| Enlistment date | |
| Rank on enlistment | Private |
| Unit name | 16th Battalion, 11th Reinforcement |
| AWM Embarkation Roll number | 23/33/3 |
| Embarkation details | Unit embarked from Adelaide, South Australia, on board HMAT A24 Benalla on |
| Rank from Nominal Roll | Private |
| Unit from Nominal Roll | 2nd ATM Battery |
| Fate | Returned to Australia |
| Miscellaneous details (Nominal Roll) | *Spelt Denis John O'Leary on NR |
| Other details |
War service: Egypt, Western Front Medals: 1914-15 Star, British War Medal, Victory Medal |