John Julian McKeithen (May 28, 1918 – June 4, 1999) was an American lawyer, politician, and the 49th governor of Louisiana, serving from 1964 to 1972.
A Democrat and attorney from the rural town of Columbia, he first served in other state offices.
In 1967 he gained passage after his first term of a constitutional amendment to allow governors to serve two successive terms.
He was the first governor of his state in the twentieth century to be elected and serve two consecutive terms.
He strongly advocated the construction of the Louisiana Superdome in New Orleans.
He had served in the US Army in the Pacific Theater during World War II.
During the Civil Rights era, in 1965 McKeithen intervened in events in Bogalusa, Louisiana, to end violence after the Ku Klux Klan continued to violently resist change for African Americans, following passage of the Civil Rights Act of 1964.
He established a commission to work on social transition in the state.