Thomas Alexander Harris (1826 – April 9, 1895) was a United States Army officer at the end of the Mexican–American War and a Missouri State Guard (Confederate) brigadier general during the early months of the American Civil War (Civil War). He then became a prominent Confederate politician, serving in the First Confederate Congress from 1861 to 1864. Among other occupations, he was a Missouri State Representative before the Civil War and a Kentucky State Representative in 1885–1886.