Hardress Lloyd was commissioned a second lieutenant in the 4th Royal Irish Dragoon Guards on 10 October 1894. He was promoted to lieutenant on 1 July 1896, and served in the Tirah Campaign on the North West Frontier in 1897–98. Joining the 21st Lancers in South Africa for the Second Boer War, he served as aide-de-camp to Lieutenant-General Sir Edward Locke Elliot between 26 March 1901 and September 1902. He resigned his commission in the 21st Lancers on 8 October 1902.