| Regimental number | 3126 |
| Place of birth | Foster Victoria |
| Religion | Church of England |
| Occupation | Grocer |
| Address | Police Station, West Footscray, Victoria |
| Marital status | Single |
| Age at embarkation | 26 |
| Next of kin | Father, Joseph Sinclair Mackay, Police Station, West Footscray, Victoria |
| Enlistment date | |
| Rank on enlistment | Private |
| Unit name | 4th Light Horse Regiment, 24th Reinforcement |
| AWM Embarkation Roll number | 10/9/3 |
| Embarkation details | Unit embarked from Melbourne, Victoria, on board HMAT A67 Orsova on |
| Rank from Nominal Roll | Trooper |
| Unit from Nominal Roll | 5th Field Artillery Brigade |
| Fate | Killed in Action |
| Age at death from cemetery records | 28 |
| Place of burial | Frenchencourt Communal Cemetery (Row B, Grave No. 4), France |
| Panel number, Roll of Honour, Australian War Memorial | 14 |
| Miscellaneous information from cemetery records | Parents: Joseph Sinclair and Sarah Ann MACKAY, Footscray Police Station, Victoria. Native of Foster, South Gippsland, Victoria |