| Regimental number | 18484 |
| Place of birth | Kinchela, New South Wales |
| School | Summer Island Public School, Mackay River, New South Wales |
| Religion | Methodist |
| Occupation | Bookkeeper |
| Address | Kinchela Creek, Macleay River, New South Wales |
| Marital status | Single |
| Age at embarkation | 21 |
| Next of kin | Father, A L Johnston, Kinchela Creek, Macleay River, New South Wales |
| Enlistment date | |
| Rank on enlistment | Gunner |
| Unit name | Field Artillery Brigade 7, Battery 25 |
| AWM Embarkation Roll number | 13/35/1 |
| Embarkation details | Unit embarked from Sydney, New South Wales, on board HMAT A8 Argyllshire on |
| Rank from Nominal Roll | Gunner |
| Unit from Nominal Roll | 3rd Division TMB |
| Other details from Roll of Honour Circular | Gunner Johnston was killed by Shell while helping to carry to shelter Corporal Stapleton of 6th French Mortar, who was badly wounded. (Father) |
| Fate | Killed in Action |
| Place of death or wounding | Peronne, France |
| Age at death | 22 |
| Age at death from cemetery records | 22 |
| Place of burial | Peronne Communal Cemetery Extension (Plot I, Row C, Grave No. 61), France |
| Panel number, Roll of Honour, Australian War Memorial | 20 |
| Miscellaneous information from cemetery records | Parents: Albert Dudley and Annie JOHNSTON, 110 Dalhousie Street, Haberfield, New South Wales. Native of Kinchela, New South Wales |
| Family/military connections | Had 8 cousins and 1 uncle who were killed in action or died of wounds. |
| Other details |
War service: Western Front Medals: British War Medal, Victory Medal |