| Regimental number | 6763 |
| Place of birth | Sydenham Road, Marrickville, New South Wales |
| School | Marrickville Public School, New South Wales |
| Religion | Presbyterian |
| Occupation | Bread carter |
| Address | 168 Sydenham Road, Marrickville, New South Wales |
| Marital status | Married |
| Age at embarkation | 27 |
| Next of kin | Wife, Mrs M K Liddell, 168 Sydenham Road, Marrickville, New South Wales |
| Enlistment date | |
| Rank on enlistment | Private |
| Unit name | 14th Battalion, 22nd Reinforcement |
| AWM Embarkation Roll number | 23/31/4 |
| Embarkation details | Unit embarked from Sydney, New South Wales, on board HMAT SS Port Napier on |
| Rank from Nominal Roll | Private |
| Unit from Nominal Roll | 29th Battalion |
| Fate | Killed in Action |
| Miscellaneous details (Nominal Roll) | *Spelt Sidney John Liddell on NR |
| Place of death or wounding | Polygon Wood, Ypres, Belgium |
| Age at death | 30 |
| Place of burial | Hooge Crater Cemetery (Plot XII,Row F, GraveNo. 9), Zillebeke, Belgium |
| Panel number, Roll of Honour, Australian War Memorial | 115 |
| Miscellaneous information from cemetery records | Parents: William and Margaret LIDDELL; husband of Mary LIDDELL, 168 Sydenham road, Marrickville, New South Wales |
| Other details |
War service: Western Front Medals: British War Medal, Victory Medal |