Alexander Douglas was born in 1883 at Junee NSW, the son of Samuel and Ruth Douglas. In 1912, at the age of  29, he married Margaret Emma Connolly (1884-1949) in Newcastle, NSW. They had two daughters, Yvonne Marguerite, known as Bonnie, on 25 September, 1915, at Essendon, Victoria, followed two years later in 1917 by Marie Alexandra. Alexander Douglas died at Collaroy, NSW in 1962.

Little can be found about Alexander Douglas's war service beyond the bare facts. He applied to enlist in the Railway Units of the AIF because he was already a railway worker and was advised to report to Melbourne Town Hall on 16 January, 1917. He enlisted on 22 January, 1917, and was sent for training at Royal Park, Carlton. On 1 February, 1917, he was promoted to Corporal and attached to Railway Unit 2. The unit embarked on 19 February the same year, on board HMAT Ballarat A 70, disembarking at Devonport, England, on 25 April, 1917. From Devoport, they marched in to Bordon, England and on 29 May, embarked for the Western Front.

He was in hospital on 2 July, only rejoining his unit on 8 September, following a severe injury to his left knee as a result of a shell blast. He had twisted it as he stepped down from the engine and the shell had thrown up sand. He was then transferred to the 14th Light Railway, then the 15th Light Railway,but on 19 December, he was returned to England suffering from traumatic synovitis of the left knee. He was admitted to the Horton War Hospital, Epsom, and was then discharged from further war service.

Alexander Douglas returned to Australia on the Kenilworth Castle on 12 March 1918. On 21 June, his discharge from further service was recommended. He died at Collaroy NSW in 1962.