Henry Edward Crampton (January 5, 1875 – February 26, 1956) was an American evolutionary biologist and malacologist who specialized in the study of land snails. Crampton undertook the first major study of evolution in nature in his research in the Society Islands. Crampton made twelve separate expeditions over the course of his career to Moorea near Tahiti to study the land snail genus Partula, while years more were spent measuring and cataloguing his specimens. In all, he dedicated nearly half-a-century to the study.
Crampton served as professor of zoology at Columbia University and Barnard College from 1904 to 1943. He was the curator of invertebrate zoology at the American Museum of Natural History. Stephen Jay Gould has cited Crampton as an inspiration, both for his evolutionary observations on Partula, and the enormous dedication and effort required to undertake them. He was also the inspiration for future work on Partula by Bryan Clarke, James Murray and Michael Johnson. This research was central to much of the development of the science of genetics.
Crampton's monographs remain some of the most remarkable publications on any species, for their meticulous detail and the beautiful illustrations they contain. His work on the Society Islands species was never finished, his monographs covering only those of Tahiti and Moorea. The volumes on Huahine, Raiatea, Tahaa and Bora Bora were never finished. This work is being revived, and the centenary of his first volume (Tahiti in 1916) is to be marked by the publication of a new monograph on all the Partulidae