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.

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.

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