| Regimental number | 5650 |
| Place of birth | Lane Cove, Sydney, New South Wales |
| School | North Sydney Public School, New South Wales |
| Religion | Presbyterian |
| Occupation | Bank clerk |
| Address | 9 Lane Cove Road, North Sydney, New South Wales |
| Marital status | Single |
| Age at embarkation | 18 |
| Next of kin | Father, Mr A B Armstrong, 189 Lane Cove Road, North 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 |
| Other details from Roll of Honour Circular | Died on Troopship Kyarra A55 |
| Fate | Died of disease |
| Place of death or wounding | On Board Ship |
| Date of death | |
| Age at death | 19 |
| Place of burial | At Sea |
| Commemoration details | Hollybrook Memorial, Southampton, England |
| Panel number, Roll of Honour, Australian War Memorial | 39 |
| Family/military connections | His brother Alexander Boswell Armstrong No 5649 was killed in action near Lagnicourt 17 April 1917; Brother: 5649 Alexander Boswell ARMSTRONG, killed in action, 15 April 1917. |
| Miscellaneous details | DIED OF ILLNESS (MENINGITIS) |