Educated at St Paul's School, Boyd enlisted into the Devonshire Regiment in 1895. He fought in the Second Boer War 1899-1901, and took part in the Relief of Ladysmith, including the actions at Colenso; and in the operations in Orange River Colony, including the action at Wittebergen. During the war, he was commissioned into the East Yorkshire Regiment in May 1900, and promoted to lieutenant in that regiment on 26 April 1902. He was mentioned in despatches three times (including 25 April 1902), received the Queen's South Africa Medal, and was appointed a Companion of the Distinguished Service Order (DSO) for his war service. He went on to be Brigade Major for 11th Infantry Brigade in 1912.