Henry Smeathman (1742–1786) was an English naturalist, best known for his work in entomology and colonial settlement in Sierra Leone.
In 1771 Quaker Physician John Fothergill, along with two other members of the Royal Society, Sir Joseph Banks and Marmaduke Tunstall, sponsored Smeathman to spend four years in and around the Sierra Leone peninsula studying its natural history, specifically its insects.
Smeathman made his voyage to Africa aboard a trade ship called the Fly, which was transporting barrels of rum to the West African coast. The Fly arrived at Sierra Leone on December 12, 1771. Smeathman was given some key contacts in West African coast including African-European slave trading families, presumably from Drury, Fothergill or Banks. With these contacts, Smeathman was first granted permission to stay in the Banana Islands, where he settled on December 17, 1771 and stayed for more than three years. Upon arrival, Smeathman presented himself to King James Cleveland, an African-European slave trader who helped him settle and explore by taking him in through negotiating terms with other members of the local ruling elite (referred to as "kings" or "chiefs" by the traders in the region). In exchange for gifts, Smeathman was given permission to settle on the islands, and he was also given help in his research. He relied on the locals to assist him in constructing a house and he bartered with them in order to obtain local resources. This dependence came about due to the lack of European settlement in his location of residence. Shortly after his arrival, Smeathman contracted a case of what he described as malaria. Though he claimed that he had cured himself with Dr. Fothergill's advice and his medical books that he had brought along, he suffered from symptoms of the disease until his death from a fever, which was fifteen years after initial exposure.