He was promoted to the rank of lieutenant in October 1899. Baird served in the Second Boer War, arriving in South Africa as a brigade signalling officer. He was present at the Relief of Kimberley in February 1900, soon after he took part in battle at Paardeberg and Poplar Gove, and the actions that immediately followed at Driefontein. From July to November 1900, he saw action in the Orange River Colony, including engagements at Bothaville and along the Caledon River. He was promoted to the rank of captain in March 1901, at which point Baird was seconded to the Foreign Office beginning in April. His actions during the war saw him mentioned in dispatches, as well as being awarded the Queen's Medal. He was made a Companion of the Distinguished Service Order in September 1901.