| Regimental number | 686 |
| Place of birth | Cheltenham Victoria |
| Religion | Roman Catholic |
| Occupation | Fireman |
| Address | Cheltenham, Vic |
| Marital status | Single |
| Age at embarkation | 21 |
| Next of kin | Will Alf. O'Neil, 12 Brunswick Road, Melbourne, Victoria |
| Enlistment date | 16 November 1914 |
| Rank on enlistment | Private |
| Unit name | 9th Light Horse Regiment, 3rd Reinforcement |
| AWM Embarkation Roll number | 10/14/2 |
| Embarkation details | Unit embarked from Melbourne, Victoria, on board HMAT A47 Mashobra on 29 January 1915 |
| Rank from Nominal Roll | Private |
| Unit from Nominal Roll | 9th Light Horse Regiment |
| Fate | Returned to Australia 16 March 1919 |
| Miscellaneous details (Nominal Roll) | *Spelt Thomas O'Neill on NR |