Lewis Wendell Hackett (14 December 1884 - Washington, 28 April 1962) was an American physician who worked in Italy and South America to combat malaria. He graduated from Harvard Medical School in 1913. The following year he became part of the International Health Division of the Rockefeller Foundation, whose task was the eradication of certain diseases of particular social importance in different parts of the world. From 1914 to 1924 he worked in Central America. In 1924 he was transferred to Italy.