| Date of birth | |
| Place of birth | Graceville, Brisbane, Queensland |
| School | Brisbane Grammar School, Queensland |
| Religion | Church of England |
| Occupation | Electrical engineer |
| Address | 'Inchbrakie', Fernberg Road, Paddington, Brisbane, Queendland |
| Marital status | Single |
| Age at embarkation | 23 |
| Height | 5' 10" |
| Weight | 142 lbs |
| Next of kin | Father, Charles William Costin, 'Inchbrakie', Fernberg Road, Paddington, Brisbane, Queendland |
| Previous military service | Served in Senior Cadets for 3.5 years; 3.5 years in the Moreton Regiment, Citizen Military Forces. |
| Enlistment date | |
| Rank on enlistment | Lieutenant |
| Unit name | 9th Battalion, Machine Gun Section |
| Embarkation details | Unit embarked from Brisbane, Queensland, on board A5, S.S. Omrah on |
| Rank from Nominal Roll | Lieutenant |
| Unit from Nominal Roll | 9th Battalion |
| Other details from Roll of Honour Circular | He invented an apparatus for cooling the machine gun whilst in action. His was the first Australian machine gun to be set up in Gallipoli. (details from mother) |
| Fate | Killed in Action |
| Place of death or wounding | Gallipoli, Turkey |
| Place of burial | No known grave |
| Commemoration details | The Lone Pine Memorial, Gallipoli, Turkey The Lone Pine Memorial, situated in the Lone Pine Cemetery at Anzac, is the main Australian Memorial on Gallipoli, and one of four memorials to men of the New Zealand Expeditionary Force. Designed by Sir John Burnet, the principal architect of the Gallipoli cemeteries, it is a thick tapering pylon 14.3 metres high on a square base 12.98 metres wide. It is constructed from limestone mined at Ilgardere in Turkey. The Memorial commemorates the 3268 Australians and 456 New Zealanders who have no known grave and the 960 Australians and 252 New Zealanders who were buried at sea after evacuation through wounds or disease. The names of New Zealanders commemorated are inscribed on stone panels mounted on the south and north sides of the pylon, while those of the Australians are listed on a long wall of panels in front of the pylon and to either side. Names are arranged by unit and rank. The Memorial stands over the centre of the Turkish trenches and tunnels which were the scene of heavy fighting during the August offensive. Most cemeteries on Gallipoli contain relatively few marked graves, and the majority of Australians killed on Gallipoli are commemorated here. |
| Panel number, Roll of Honour, Australian War Memorial | 55 |
| Miscellaneous information from cemetery records | Parents: Charles William and Ellen O'Donnell COSTIN, Fernberg Road, Paddington, Brisbane, Queensland |
| Other details |
War service: Egypt, Gallipoli Medals: 1914-15 Star, British War Medal, Victory Medal |
| Sources | NAA: B2455, COSTIN Joseph William |