| Regimental number | 124 |
| Place of birth | Dungog, New South Wales |
| Religion | Presbyterian |
| Occupation | Farmer |
| Address | Bandon Grove, via Dungog, New South Wales |
| Marital status | Single |
| Age at embarkation | 28 |
| Height | 5' 5" |
| Weight | 118 lbs |
| Next of kin | Father, J E Irwin, Bandon Grove, via Dungog, New South Wales |
| Previous military service | Served in the 6th Light Horse Regiment, Citizen Military Forces; still serving at time of AIF enlistment. |
| Enlistment date | |
| Place of enlistment | Sydney, New South Wales |
| Rank on enlistment | Corporal |
| Unit name | 1st Light Horse Regiment, A Squadron |
| AWM Embarkation Roll number | 10/6/1 |
| Embarkation details | Unit embarked from Sydney, New South Wales, on board HMAT A16 Star of Victoria on |
| Rank from Nominal Roll | Corporal |
| Unit from Nominal Roll | 1st Light Horse Regiment |
| Fate | Returned to Australia |
| Discharge date | |
| Family/military connections | Brother: 5130 Pte Alexander Joseph IRWIN, 5th Division Headquarters, returned to Australia, 4 January 1919. |
| Other details |
War service: Egypt Commenced return to australia from Suez on board HT 'Kyarra', 5 February 1915; discharged (medically unfit: weak heart, loss of memory), 3 May 1915 |
| Sources | NAA: B2455, IRWIN Walter George |