Allen Joseph Ellender (September 24, 1890 - July 27, 1972) was a U.S. political figure who served as a Democratic United States Senator from Louisiana from 1937 until his death in 1972. He served as the president pro tempore of the U.S. Senate between 1971 and 1972. He also served as the chairman of the Senate Agriculture Committee from 1951 to 1953 and 1955 to 1971, and as Chairman of the Senate Appropriations Committee from 1971 until 1972. Ellender, along with Ralph Flanders of Vermont, was a vociferous opponent of McCarthyism and attacked the tactics of Senator Joseph McCarthy.