Thomas Campbell Clark (September 23, 1899 – June 13, 1977) was an American lawyer who served as the 59th United States attorney general from 1945 to 1949 and as Associate Justice of the Supreme Court of the United States from 1949 to 1967.
Clark was born in Dallas, Texas, and graduated from the University of Texas School of Law after serving in World War I. He practiced law in Dallas until 1937, when he accepted a position in the U.S. Department of Justice. After Harry S. Truman became President of the United States in 1945, he chose Clark as his Attorney General. In 1949, Truman successfully nominated Clark to fill the U.S. Supreme Court vacancy caused by the death of Associate Justice Frank Murphy, making Clark the first and, as of 2026, only Supreme Court Justice from the state of Texas. Clark remained on the Court until retiring to allow his son, Ramsey Clark, to assume the position of U.S. Attorney General. Clark was succeeded by the first African American Supreme Court Justice, Thurgood Marshall, in October 1967.
Clark served on the Vinson Court and the Warren Court. He voted with the Court's majority in several cases concerning racial segregation, including the landmark case of Brown v. Board of Education. He wrote the majority opinion in landmark Mapp v. Ohio, which ruled that the Fourth Amendment prohibition against unreasonable searches and seizures applies to the states through the Fourteenth Amendment. He also wrote the majority opinion in Heart of Atlanta Motel v. United States, which upheld the public accommodations provision of the Civil Rights Act of 1964, and the majority opinions in Garner v. Board of Public Works, Joseph Burstyn, Inc. v. Wilson, Abington School District v. Schempp (which found that mandatory Bible reading in public schools was unconstitutional), and the "aggressively anti-homosexual" Boutilier v. Immigration and Naturalization Service.
