| Regimental number | 3726 |
| Religion | Presbyterian |
| Occupation | Labourer |
| Address | Chillingollah, Victoria |
| Marital status | Single |
| Age at embarkation | 19 |
| Next of kin | Father, John O'Brien, 85 Victoria Street, St. Albans, Herts, England |
| Enlistment date | 21 April 1917 |
| Rank on enlistment | Private |
| Unit name | 4th Light Horse Regiment, 29th Reinforcement |
| AWM Embarkation Roll number | 10/9/4 |
| Embarkation details | Unit embarked from Sydney, New South Wales, on board HMAT A68 Anchises on 8 August 1917 |
| Rank from Nominal Roll | Gunner |
| Unit from Nominal Roll | 14th Field Artillery Brigade |
| Fate | Returned to Australia 8 July 1919 |
