He was the second son of the Hon. Thomas Vesey Dawson, an officer of the Coldstream Guards who was killed at the Battle of Inkerman. His paternal grandfather was Richard Thomas Dawson, 2nd Baron Cremorne. His elder brother, Vesey, was also a British Army officer.
He attended Eton College, and then joined the Coldstream Guards in 1874, attending the Staff College in 1881. He saw service with the Egyptian Campaign of 1882, where he fought at the battles of Mahuta, Kassassin, Tel el-Kebir and the capture of Cairo. In the Nile Expedition of 1884-85, he was part of the Guards' Camel Corps, was mentioned in despatches, and saw action at the Battle of Abu Klea. He was then appointed a Military Attaché from 1895 to 1901, posted to Austria-Hungary, Serbia, France, Belgium and Switzerland, before returning to the United Kingdom as Master of the Ceremonies to King Edward VII from 1903–1907 and then as a Comptroller in the Lord Chamberlain's Department.
On the outbreak of the First World War he received a War Office appointment as ADPS[clarification needed] from 1914 to 1915, and was appointed Inspector of Vulnerable Points at GHQ from 1916 to 1919, in which role he was again mentioned in despatches. After the War, in 1920, he resigned his position as Comptroller and was appointed State Chamberlain, holding the office until 1924.
Partly as a result of his diplomatic career, he held a number of foreign decorations, including the Iron Crown of Austria (Knight Commander); the Turkish Order of Medjidie (3rd class); the Danish Order of Dannebrog (Grand Cross); the Japanese Grand Cross Sacred Treasure and Grand Cross Rising Sun; the Grand Cross of the Crown of Italy; and the Grand Cross of the Crown of Romania. He served as the Registrar and Secretary to the Order of the Bath, and the Secretary to the Order of the Garter.
He married Aimée Evelyn Pirie, formerly Mrs. Oakley in 1903, who was named Dame Grand Cross of the Order of the British Empire in 1918. Sir Douglas and Lady Aimée Dawson lived at Medmenham Abbey in Buckinghamshire. Their daughter, Rosemary, married Lieutenant-Colonel Vernon Erskine-Crum; the couple had one son, Brigadier Douglas Erskine Crum.
- Lundy, Darryl. "Aimée Dawson profile". The Peerage.
- Lundy, Darryl. "Douglas Dawson profile". The Peerage.
- Obituary in The Times.
- Who Was Who (Online edition ed.). A & C Black. 2007. (subscription required)