Warren Eastman Hearnes (born July 24, 1923) is an American politician who was Governor of Missouri from 1965 to 1973. He was a Democrat.

Hearnes served in the U.S. Army during World War II and was a member of Missouri state house of representatives between 1950 and 1961; he was the Secretary of State of Missouri between 1961 and 1965. He was elected governor in 1964 and re-elected in 1968. He was a candidate for the Senate in 1976.

His wife, Betty C. Hearnes , was the first woman to run for the Governor of Missouri.