Samuel Stehman Haldeman (August 12, 1812 - September 10, 1880) was an American naturalist and philologist. He studied a wide range of subjects, including biology, zoology, entomology, geology, chemistry, and paleontology. At the age of 23, Samuel contributed to the Lancaster Journal an article refuting Locke's "Moon Hoax". From then on, his life was devoted to science. In 1844 he became a member of the American Association for the Advancement of Science. Haldeman was the only American Naturalist with whom Charles Darwin corresponded, and whose opinion Darwin regarded as authoritative." He continued to write important and prize-winning essays and articles in philology, ethnology, and natural history. He died in 1880 at the age of 68.