Thurman Wesley Arnold was an American lawyer best known for his trust-busting campaign as Assistant Attorney General in charge of the Antitrust Division in President Franklin D. Roosevelt's Department of Justice from 1938 to 1943. He later served as a Judge on the United States Court of Appeals for the District of Columbia. Before coming to Washington in 1938, Arnold was the mayor of Laramie, Wyoming and a professor at Yale Law School, where he took part in the legal realism movement and published two books: The Symbols of Government (1935) and The Folklore of Capitalism (1937). He also published The Bottlenecks of Business (1940).