Dickson was born in St Helier, the son of Major-General E J Dickson and his wife Louisa Maria, nee Anley. After studying at Cheltenham College and the Royal Military College Sandhurst, he was commissioned into the 49th Regiment of Foot in 1869. He married Helene Frances Harvey, eldest daughter of Colonel W F Harvey, in 1878, and they had one daughter.
In the Suakin Expedition of 1885 he saw action at the Battles of Suakin, Hasheen, Tofrek, and Ginnis, and was appointed brigade-major in the Sudan Field Force. He was later appointed to command the 1st Battalion Royal Berkshire Regiment from 1891 to 1895, and the 49th Regimental District from 1897 to 1902. In 1902 he was appointed to the staff in Barbados, and in 1905 promoted to the post of General Officer Commanding the forces in West Africa.
In 1906 he returned to England as the Major-General responsible for administration in Eastern Command, a post he held until 1908. That year, he was appointed the first General Officer Commanding of the newly formed West Lancashire Division in the Territorial Force, and in 1909 took command of the Home Counties Division. He remained in command of the division until 1912, when he retired to Tunbridge Wells.