| Regimental number | 1310 |
| Place of birth | Sydney, New South Wales |
| Place of birth | Ashfield, Sydney, New South Wales |
| Other Names | Con |
| School | Ashfield Private School, New South Wales |
| Religion | Presbyterian |
| Occupation | Assayer |
| Marital status | Single |
| Age at embarkation | 25 |
| Height | 5' 6" |
| Weight | 147 lbs |
| Next of kin | Father, Mr T. C. Allen, Kirribilli Point, North Sydney, New South Wales |
| Previous military service | Nil |
| Enlistment date | |
| Date of enlistment from Nominal Roll | |
| Place of enlistment | Liverpool, New South Wales |
| Rank on enlistment | Private |
| Unit name | 2nd Battalion, 2nd Reinforcement |
| Embarkation details | Unit embarked from Sydney, New South Wales, on board HMAT A48 Seang Bee on |
| Rank from Nominal Roll | Private |
| Unit from Nominal Roll | 2nd Battalion |
| Other details from Roll of Honour Circular | Held a responsible position in Smelting works at Chilagoc, QLD, he had many men under him. (Father) |
| Fate | Killed in Action |
| Place of death or wounding | Gallipoli, Turkey |
| Age at death | 26 |
| Place of burial | Lone Pine Cemetery (Plot I, Row C, Grave 13), Gallipoli, Turkey. |
| Panel number, Roll of Honour, Australian War Memorial | 31 |
| Miscellaneous information from cemetery records | Parents: Thomas Con and Aileen ALLEN |
| Other details |
War service: Egypt, Gallipoli Embarked Alexandria to join the Mediterranean Expeditionary Force (Gallipoli Campaign), 5 April 1915. Killed in action, 1 May 1915. Medals: 1914-15 Star, British War Medal, Victory Medal |
| Sources | NAA: B2455, ALLEN Con Harold |