Isaac Thomas was an American politician representing Tennessee in the United States House of Representatives. He was born in Sevierville, Tennessee on November 4, 1784. After the death of his parents, he moved to Winchester, Tennessee in 1800. He was self-educated, and he studied law. He was admitted to bar in 1808 and practiced in Winchester. He was elected as a Democratic-Republican to the Fourteenth Congress, which lasted from March 4, 1815 to March 3, 1817.
Afterward, he moved to Alexandria, Louisiana in 1819 and resumed the practice of law. He purchased vast tracts of land adjoining Alexandria and became one of the largest landowners and slaveholders in Louisiana. He was the first man to introduce the cultivation of sugarcane in central Louisiana. He also engaged in mercantile pursuits and in the operation of sawmills and steamboats.
He served as brigadier general of the Louisiana Militia during the War of 1812 and served as a member of the Louisiana Senate from 1823 to 1827. He moved to California in 1849. He returned to Alexandria, Louisiana, where he died on February 2, 1859. He was interred in Flint lot, in Rapides Cemetery, at Pineville, Louisiana.