| Regimental number | 4136 |
| Place of birth | Gunnedah New South Wales |
| Religion | Roman Catholic |
| Occupation | Shearer |
| Address | 38 Marion Street, Leichhardt, Sydney, New South Wales |
| Marital status | Single |
| Age at embarkation | 29 |
| Next of kin | Father, John Mahon, 38 Marion Street, Leichhaqrdt, Sydney, New South Wales |
| Enlistment date | |
| Rank on enlistment | Private |
| Unit name | 1st Pioneer Battalion, 11th Reinforcement |
| AWM Embarkation Roll number | 14/13/5 |
| Embarkation details | Unit embarked from Sydney, New South Wales, on board HMAT A72 Beltana on |
| Rank from Nominal Roll | Private |
| Unit from Nominal Roll | 1st Pioneer Battalion |
| Fate | Returned to Australia |
| Family/military connections | Brother: 12009 Pte John Thomas MAHON, 9th Field Ambulance, returned to Australia, 2 June 1919. |
| Other details |
War service: Western Front Medals: British War Medal, Victory Medal |