| Regimental number | 7/993 |
| Address | Fendalton, Christchurch |
| Marital status | Single |
| Next of kin | Mother, Mrs Annie O'Callaghan, Webbs Road, Fendalton, Christchurch |
| Rank on embarkation | Sergeant |
| Enlistment status | Volunteer |
| Unit name | New Zealand Expeditionary Force, 4th Reinforcements, Canterbury Mounted Rifles |
| Embarkation details | Unit embarked from Wellington on board HMNZT 23 Waitomo on 17 April 1915 |
| Family/military connections | Brother: 7/992 Trooper Vivian Gerald O'CALLAGHAN |
| Miscellaneous details | Nominal Roll Vol. 1: Canterbury Mounted Rifles/Fourth |
