Dutton was commissioned a second lieutenant in the Cameronians (Scottish Rifles) on 21 October 1893, promoted to a lieutenant on 15 November 1895, and to a captain on 23 August 1899. He served in the Second Boer War from 1899 to 1902 with the 2nd Battalion of his regiment. They were with the Ladysmith relief force, and took part in the battles of Colenso (15 December 1899), Spion Kop (January 1900), Vaal Krantz and Tugela Heights (February 1900). Following the relief of Ladysmith on 1 March 1900, he served in Natal from March to June 1900, and was present at the action at Laing's Nek. From July until November 1900 he served in Transvaal east of Pretoria. After the war ended in June 1902, Dutton returned to the United Kingdom the following month, and arrived at Southampton in August.