The United States Information Agency (USIA), which operated from 1953 to 1999, was a United States government agency devoted to the practice of public diplomacy. In 1999, prior to the reorganization of intelligence agencies by President George W. Bush, President Bill Clinton assigned USIA's cultural exchange and non-broadcasting intelligence functions to the newly created under secretary of state for public diplomacy and public affairs at the U.S. Department of State. USIA's broadcasting functions were moved to the newly created Broadcasting Board of Governors. The agency was previously known overseas as the United States Information Service (USIS), operating out of U.S. embassies worldwide. Since the merger of USIA with the Department of State, public diplomacy and public affairs sections at U.S. missions have carried on this work.

Former USIA Director of TV and Film Service Alvin Snyder recalled in his 1995 memoir that "the U.S. government ran a full-service public relations organization, the largest in the world, about the size of the twenty biggest U.S. commercial PR firms combined. Its full-time professional staff of more than 10,000, spread out among some 150 countries, burnished America‘s image and trashed the Soviet Union 2,500 hours a week with a 'tower of babble' comprised of more than 70 languages, to the tune of over $2 billion per year". The USIA was "the biggest branch of this propaganda machine."