Warren Cowgill (; December 19, 1929 – June 20, 1985) was an American linguist.
He was a professor of linguistics at Yale University and the Encyclopædia Britannica's authority on Indo-European linguistics.
He was unusual among Indo-European linguists of his time in believing that Indo-European should be classified as a branch of Indo-Hittite, with Hittite as a sister language of the Indo-European languages, rather than a daughter language.
Warren Cowgill and his twin brother, anthropologist George Cowgill, were born near Grangeville, Idaho.
Along with his brother, he graduated from Stanford University in 1952 and received a Ph.D.
from Yale in 1957.
He was a member of the Yale faculty in the Department of Linguistics until his death in 1985.