Millard Fillmore Caldwell (February 6, 1897—October 23, 1984) was an American politician. He was the 29th governor of Florida (1945–1949) and served in all three branches of government at various times in his life, including as a U.S. Representative and Florida Supreme Court justice.

Caldwell was born in the rural area of Beverly, Tennessee, outside Knoxville. There he attended public schools and attended Carson-Newman College, the University of Mississippi, and the University of Virginia. During World War I, Caldwell enlisted in the U.S. Army on April 3, 1918. He was commissioned as a second lieutenant in the Field Artillery, and was discharged on January 11, 1919.

Caldwell was married to Mary Harwood Caldwell; the couple's three children were Susan, Millard, and Sally. Caldwell moved to Milton, Florida in 1924, practicing law there. In 1926, he began serving as prosecutor and county attorney of Santa Rosa County; in 1929, he was elected as a conservative Democrat to the State House, where he was a member until 1932.

That year, Caldwell was elected to the U.S. House as the representative from Florida's third district. He took office on March 4, 1933, and served three terms, ending on January 3, 1941. In 1944, Caldwell was elected governor of Florida. Taking office in 1945, Caldwell's term is noted for his segregationist beliefs, as well as his support for road construction projects and the establishment of the Educational Minimum Foundation Program, which gave education funds to rural counties. One of the more colorful aspects of Caldwell's term came on August 10, 1945, during the surrender of Japan in World War II, when Caldwell issued a proclamation urging bars and other alcohol-selling establishments to close in order to prevent a frenzy of drunken celebration in the streets.

After leaving office in 1949, Caldwell was appointed the administrator of the Federal Civil Defense Administration by then-President Harry S. Truman in 1950. This appointment was opposed by the NAACP because of Caldwell's segregationist record. After leaving this post in 1952, Caldwell served as a justice — and later chief justice — on the State Supreme Court from 1962 to 1969.

Caldwell died in Tallahassee on October 23, 1984. He was buried at Harwood Plantation Cemetery in Leon County.

During his life, Caldwell was a member of the Newcomen Society, Freemasons, Shriners, Elks, and Knights of Pythias, in addition to Kappa Sigma and Phi Alpha Delta.