Douglas was born in East Melbourne on 5th May, 1889, the youngest son and child of George Hamilton Dougharty and Catherine (Kate) Grey Dougharty (nee Innes). Douglas had 2 older brothers and 5 sisters, some of whom were also involved directly with WWI.(see later notes) His father George, was of Scottish origin, a cousin of the tenth Duke of Hamilton and last Earl of Coventry. Upon purchasing their home at 154 Hotham Street in 1883, it was named 'Cadzow' after Cadzow Castle, the seat of his Scottish Hamilton family. In 1874, George married Catherine, the eldest daughter of Mr. F.M. Innes, a previous Tasmanian Premier, in Hobart where he was living at that time, moving to East Melbourne before Douglas was born. George and his brother John Hamilton Dougharty, (a Victoria magistrate and MLC) conducted a large stock and station business for over 40 years.

Douglas enlisted for service on 11th November, 1915 in Ross, Tasmania. His occupation at the time is noted as Clerk and he was 24 years old. In March 1916 he embarked from Australia on HMAT Shropshire A9 to London where he worked at the Convelescent Depot, Harefield Auxiliary Hospital near London. In July 1916 he was transferred to the Austalian Dermological Hospital, Bulford. Late September 1916 he proceeded to France to join the 2nd Field Ambulance reinforcements where he remained until the end of the war apart from transferring to a temporary position in February 1917 with the 1st South Midland Casualty Clearing Station. He took leave in May 1918 in St Andrew's, Fife where his sister Jean was based at St Salvator's College, St Andrew's University. In January 1919 Douglas was granted 6 months leave to study the textile industry at Halifax Technical College, North England. After successfully passing this course, he was granted a further 6 months leave to gain work experience with R Moore & Sons, Bradford. In August 1919 he returned to Australia in good health and was discharged from service early December.

His older brother Frederick  aged 39, a married Bank Clerk living in Launceston enlisted in 1916 and was killed in action in France on 24th April 1918. In his Red Cross file are letters from Douglas seeking information which led him to be able to see his brother's grave. Another letter places sister Isabel in London as Director for Wounded Nurses. There is no organistion noted.

On returning to Melbourne Douglas lived at Cadzow until the home was sold in 1952. It appears he remained unmarried and working as a clerk until he retired after leaving East Melbourne. In 1950 a shipping record exists for return from London, with an address c/o Dalgety in London. He moved to Boronia, Box Hill then East Malvern. He passed away in 1970 and is buried at the Box Hill Cemetery.