Carroll Milton Williams (December 2, 1916 in Oregon Hill, Virginia — October 11, 1991 in Watertown, Massachusetts) was an American zoologist known for his work in entomology and developmental biology—in particular, metamorphosis in insects,[3] for which he won the George Ledlie Prize.

He performed groundbreaking surgical experiments on larvae and pupae,[4] and developed multiple new techniques, including the use of carbon dioxide as an anesthetic.

In the most famous one, he cut a pupa in half and connected the two halves with a small tube, to study the effect of the lesions on the metamorphosis.

[10] Next he studied the endocrine control of the development of the giant American silkworm Hyalophora cecropia, introducing carbon dioxide as a surgical anesthetic.

With his students he studied cocoon-spinning behavior and the profound metabolic shutdown during diapause, and was the first to discover and isolate cocoonase and cytochrome b5,[11] as well as the "paper factor".