| Regimental number | 1293 |
| Place of birth | Lang Lang Victoria |
| Religion | Church of England |
| Occupation | Farmer |
| Address | Oaklands, New South Wales |
| Marital status | Single |
| Age at embarkation | 22 |
| Next of kin | Father, Arthur King Trethowan, Clear Hills, Oaklands, New South Wales |
| Enlistment date | 1 March 1916 |
| Rank on enlistment | Private |
| Unit name | 37th Battalion, D Company |
| AWM Embarkation Roll number | 23/54/1 |
| Embarkation details | Unit embarked from Melbourne, Victoria, on board HMAT A34 Persic on 3 June 1916 |
| Rank from Nominal Roll | Private |
| Unit from Nominal Roll | 37th Battalion |
| Fate | Returned to Australia 18 October 1917 |
| Family/military connections | Brother: 1294 Pte John Arthur TRETHOWAN, 5th Bn, returned to Australia, 25 January 1919. |
| Date of death | 16 November 1979 |
| Place of burial | Point Clare Cemetery |
