| Regimental number | 29160 |
| Place of birth | Glen Innes, New South Wales |
| School | Private Tutors |
| Religion | Church of England |
| Occupation | Private secretary |
| Address | Glen Innes, New South Wales |
| Marital status | Single |
| Age at embarkation | 30 |
| Next of kin | Sister, V J H St Clair, Lambert Street, Glen Innes, New South Wales |
| Previous military service | Nil |
| Enlistment date | |
| Date of enlistment from Nominal Roll | |
| Rank on enlistment | Gunner |
| Unit name | Howitzer Brigade 116 |
| AWM Embarkation Roll number | 13/136/1 |
| Embarkation details | Unit embarked from Sydney, New South Wales, on board HMAT A60 Aeneas on |
| Rank from Nominal Roll | Gunner |
| Unit from Nominal Roll | 1st Field Artillery Brigade |
| Other details from Roll of Honour Circular | Charles Matthew St Clair was wounded while on his way back from delivering a message to an Officer at Zelebecke Lake. Charles St Clair was spoken of as being one of the bravest and best. |
| Fate | Died of wounds |
| Miscellaneous details (Nominal Roll) | *Given name Charles Matthew |
| Place of death or wounding | Zillebeke, near Ypres, Belgium |
| Age at death | 31 |
| Age at death from cemetery records | 31 |
| Place of burial | Lijssenthoek Military Cemetery (Plot XVI, Row H, Grave No. 5A), Belgium |
| Panel number, Roll of Honour, Australian War Memorial | 11 |
| Miscellaneous information from cemetery records | Parents: Matthew and Charlotte ST. CLAIR |
| Family/military connections | Cousin: Christoper St Clair (Gunner), who was killed in August 1919. |
| Other details |
War service: Western Front Medals: British War Medal, Victory Medal |