On 1 March 1894, Findlay was made adjutant. He was promoted to the rank of major on 21 December 1896, and transferred into the Royal Field Artillery when that branch was created on 1 July 1899. He served in the Second Boer War, seeing action in Natal and Transvaal and taking part in the Relief of Ladysmith. Findlay commanded Lieutenant-General Redvers Buller's ammunition column and was mentioned in despatches on two occasions. He received the Queen's South Africa Medal with six clasps for his participation in the campaign.