| Regimental number | 5747 |
| Place of birth | Casino, New South Wales |
| Religion | Roman Catholic |
| Occupation | Jockey |
| Address | Market Street, Randwick, Sydney, New South Wales |
| Marital status | Single |
| Age at embarkation | 31 |
| Next of kin | Father, Mr J McMahon, Market Street, Randwick, Sydney, New South Wales |
| Enlistment date | |
| Rank on enlistment | Private |
| Unit name | 4th Battalion, 18th Reinforcement |
| AWM Embarkation Roll number | 23/21/4 |
| Embarkation details | Unit embarked from Sydney, New South Wales, on board HMAT A55 Kyarra on |
| Rank from Nominal Roll | Private |
| Unit from Nominal Roll | 4th Battalion |
| Fate | Returned to Australia |
| Miscellaneous information from cemetery records | Parents: John and Elizabeth MCMAHON |
| Other details |
War service: Western Front Medals: British War Medal, Victory Medal |
| Date of death | |
| Age at death | 53 |
| Place of burial | Waverley Cemetery, New South Wales |