William Morton Wheeler (March 19, 1865 - 1937) was an American entomologist, myrmecologist and Harvard Professor.

Wheeler was trained as an insect embryologist, having studied under Baur, Dohrn and Whitman, but became the leading authority on behaviour of social insects, with particular distinction being achieved in the field of ants . He took particular interest in the evolution of social behaviour in ants. He was instrumental in the development of ethology and first popularized the term in a 1902 paper in Science.

He was a taxonomist of the highest order, and was responsible for the descriptions of innumerable species.

A close contact of the British myrmecologist and coleopterist Horace Donisthorpe, it was to Wheeler that Donisthorpe dedicated his first major book on ants in 1915. Donisthorpe and Wheeler also frequently exchanged specimens, leading the latter to first develop the idea that the Formicinae subfamily had its origins in North America.