Johnston, Sir Harry Hamilton (1858–1927), a British administrator and explorer. He was born in London, and attended King's College, London, and the Royal Academy of Arts. During the 1880's he explored many regions in Africa and held consular posts.

Johnston led an expedition in 1889 to Lake Tanganyika and Lake Nyasa, hoping to create an entirely British-controlled route from Cape Town to Cairo. In 1891 Nyasaland became the British Central African Protectorate, with Johnston as commissioner and consul general, 1891–96. He also administered what is now Zambia for Cecil Rhodes's British South Africa Company. Johnston was knighted in 1896. As special commissioner of Uganda Protectorate, 1899–1901, he established a policy of forbidding land ownership by whites.

Johnston received a number of awards for his zoological and botanical findings. He discovered the okapi, a rare animal related to the giraffe. Johnston wrote many books about Africa.