General Sir Henry Augustus Smyth KCMG FSA FRGS (25 November 1825 - 19 September 1906) was a senior British Army officer. He was the son of Admiral William Henry Smyth and the brother of astronomer Charles Piazzi Smyth and geologist Sir Warington Wilkinson Smyth. Of his sisters, Henrietta married the theologian Baden Powell and Georgiana the anatomist Sir William Henry Flower.