| Regimental number | 5967 |
| Place of birth | Sydney New South Wales |
| Religion | Presbyterian |
| Occupation | Clerk |
| Address | 'Devoncourt', Burwood Road, Concord, Sydney, New South Wales |
| Marital status | Single |
| Age at embarkation | 26 |
| Next of kin | Father, William Longmuir, 'Devoncourt', Burwood Road, Concord, Sydney, New South Wales |
| Enlistment date | 22 November 1915 |
| Rank on enlistment | Sapper |
| Unit name | 7th Field Company Engineers, Reinforcement 3 |
| AWM Embarkation Roll number | 14/26/2 |
| Embarkation details | Unit embarked from Sydney, New South Wales, on board HMAT A54 Runic on 20 January 1916 |
| Rank from Nominal Roll | Lance Corporal |
| Unit from Nominal Roll | Australian Army Medical Corps |
| Fate | Returned to Australia 18 October 1917 |
| Family/military connections | Brothers: 3324 Pte William Keith LONGMUIR, Australian Army Medical Corps, returned to Australia, 19 April 1919; 2434 Corporal Ronald Stuart LONGMUIR, 53rd Bn, returned to Australia, 15 May 1919. |
| Other details | Medals: British War Medal, Victory Medal |
| Miscellaneous details | Name recorded on Embarkation roll as Collin Kennith LONGMUIR. |
