| Regimental number | 3996 |
| Place of birth | Northcote, Victoria |
| School | Samaritan Convent School; Christian Brothers College, West Melbourne, Victoria |
| Religion | Roman Catholic |
| Occupation | Carter |
| Address | 14 Christmas Street, Northcote, Victoria |
| Marital status | Single |
| Age at embarkation | 25 |
| Height | 5' 10.5" |
| Weight | 147 lbs |
| Next of kin | Father, P McMahon, 14 Christmas Street, Northcote, Victoria |
| Previous military service | Nil |
| Enlistment date | |
| Date of enlistment from Nominal Roll | |
| Place of enlistment | Melbourne, Victoria |
| Rank on enlistment | Private |
| Unit name | 7th Battalion, 12th Reinforcement |
| AWM Embarkation Roll number | 23/24/3 |
| Embarkation details | Unit embarked from Melbourne, Victoria, on board HMAT A40 Ceramic on |
| Rank from Nominal Roll | Private |
| Unit from Nominal Roll | 59th Battalion |
| Fate | Killed in Action |
| Age at death from cemetery records | 26.6 |
| Place of burial | No known grave |
| Commemoration details | V.C. Corner (Panel No 17), Australian Cemetery Memorial, Fromelles, France |
| Panel number, Roll of Honour, Australian War Memorial | 168 |
| Miscellaneous information from cemetery records | Parents: Patrick Joseph and Bridget McMAHON, 14 Christmas Street, Northcote, Victoria |
| Other details |
War service: Egypt, Western Front Allotted to and proceeded to join 59th Bn, Tel el Kebir, 26 February 1916. Embarked Alexandria to join the British Expeditionary Force, 18 June 1916; disembarked Marseilles, France, 29 June 1916. Posted missing, 19 July 1916. Fate subsequently determined as 'Killed in Action, 19 July 1916'. Handwritten note on Form B103: 'Presume Buried In No Man's Land approx 5J90 43 to 5K02.5.1 Sheet Hazebrouck 5A' Statement, 3598 Pte L.A. OAKLEY, A Company, 59th Bn, 16 March 1917: 'Witness saw soldier killed at Fleurbaix on July 19th 1916, about 70 yards from the German trenches. During the charge, soldier was carrying a number of bombs, when a shell exploded, and blew him to pieces. Witness was wounded by the same shell.' Medals: 1914-15 Star, British War Medal, Victory Medal |
| Sources | NAA: B2455, McMAHON Thomas Joseph
Red Cross File No 1950913 |