He fought in the Second Boer War between 1899 and 1902, where he took part in the Relief of Ladysmith, including the battles of Colenso (15 December 1899), Spion Kop (20–24 January 1900), Vaal Krantz (5–7 February 1900), and the Tugela Heights and Pieter's Hill (14–27 February 1900). In the following months he took part in operations in Natal March to June, and in the Orange River Colony until November 1900. He was mentioned in despatches on 10 September 1901, and appointed a Companion of the Distinguished Service Order (DSO) for his service during the war. After peace was declared in May 1902, Makins left South Africa on board the SS "Bavarian" and arrived in the United Kingdom the following month. He was promoted to major on 3 September 1902, and received the insignia of the DSO from King Edward VII following troop inspections on 4 November 1902.