| Regimental number | 9457 |
| Place of birth | Mogil Mogil, New South Wales |
| School | Christian Brothers, New South Wales |
| Religion | Roman Catholic |
| Occupation | Commercial traveller |
| Address | Dagworth, Thomas Street, Lewisham, New South Wales |
| Marital status | Single |
| Age at embarkation | 30 |
| Next of kin | Father, Edward F Coolahan, Dagworth, Thomas Street, Lewisham, New South Wales |
| Previous military service | Nil |
| Enlistment date | |
| Rank on enlistment | Driver |
| Unit name | Army Service Corps 20, Reinforcement 2 |
| AWM Embarkation Roll number | 25/106/2 |
| Embarkation details | Unit embarked from Sydney, New South Wales, on board HMAT A35 Berrima on |
| Rank from Nominal Roll | Driver |
| Unit from Nominal Roll | 14th Company, Australian Army Service Corps |
| Fate | Died of disease |
| Age at death | 33 |
| Age at death from cemetery records | 30 |
| Place of burial | Lijssenthoek Militry Cemetery (Plot X, Row B, Grave No. 20A), Belgium |
| Panel number, Roll of Honour, Australian War Memorial | 181 |
| Miscellaneous information from cemetery records | Parents: Edward and Bridget COOLAHAN, Susan Street, Randwick, New South Wales. Native of Lewisham, New South Wales |
| Family/military connections | Brothers: 8368 Driver Ernest COOLAHAN, Australian Army Service Corps, returned to Australia, 12 May 1919; 8366 Driver Maurice Stanley COOLAHAN, Australian Army Service Corps, returned to Australia, 22 February 1917; 8367 Driver Percy Bede COOLAHAN, 14th Company, Australian Army Service Corps, returned to Australia, 12 May 1919; Cousin: Lt John Stephen COOLAHAN MC, 4th Bn, died while a prisoner of war, 3 May 1918. |
| Other details |
War service: Egypt, Western Front Medals: British War Medal, Victory Medal |