British engineer, surveyor, explorer and administrator from Sutton Court in Chew Magna, Somerset, who joined the East India Company's Corps of Sappers and Miners. He became an administrator in the public works department of the government of India (1858-1865), rising to permanent secretary. Strachey had a number of official posts until appointed member of the council of the secretary of state for India (1875-1889), resigning to become chairman of the East Indian Railway Company. Involved with finance of India over many years, he attended the International Monetary Conference at Brussels (1892) as delegate for British India. For his services he was made Knight Grand Commander of the Order of the Star of India (GCSI). His scientific contributions included geography and meteorology and he was largely reponsible for founding the Indian meteorological department. Strachey was elected Chairman of the Meteorological Council of the Royal Society (1883) and President of the Royal Geographical Society (1888-1890). His son was the Victorian biographer and essayist Giles Lytton Strachey (1880-1932).

Most of his botanical specimens are from the north-western Himalaya and adjacent parts of Tibet (1840-1849), collected with fellow surveyor R.E. Winterbottom, and he subsequently produced a catalogue (1852). The genus Stracheya Benth. and many Himalayan species were named in his honour. His original collections, including types, were donated to BM and K. Cryptogamic collections made by Strachey and Winterbottom were transferred from K to BM after 1960 under the terms of the Morton Agreement.