Theo Ashton Thompson (March 31, 1916 – July 1, 1965) was a U.S. Representative from Louisiana's 7th congressional district in the southwestern corner of the state.

Born in Ville Platte in Evangeline Parish in south Louisiana, Thompson attended public schools there. From 1932 to 1934, he completed a two-year course in higher accounting at Louisiana State University in Baton Rouge. From 1934 to 1940, Thompson was the traveling auditor for the Louisiana Highway Commission. In 1942, he was the Louisiana representative at the National Assembly of the States in the development of the civil defense program at a convention held in Chicago, Illinois.

Thompson was elected as a Democrat to the Eighty-third and to the six succeeding Congresses and served from January 3, 1953, until his death July 1, 1965, in an automobile accident in Gastonia, North Carolina. While in Congress he was a signatory to the 1956 Southern Manifesto that opposed the desegregation of public schools ordered by the Supreme Court in Brown v. Board of Education. He was interred at Evangeline Memorial Park Cemetery in Ville Platte.

Thompson was succeeded in Congress by the future Governor Edwin Washington Edwards, then a state senator from Acadia Parish.

• List of United States Congress members who died in office (1950–99)