In the United States, the informal term "czar" (or, less often, "tsar") is employed in media and popular usage to refer to high-level executive-branch officials who oversee a particular policy field. There have never been any U.S. government offices with the formal title "czar". The earliest known use of the term for a U.S. government official was in the administration of Franklin Roosevelt (1933–1945), during which eleven unique positions (or twelve if one were to count "economic czar" and "economic czar of World War II" as distinct) were so described.
The list of those identified as "czars" is based on inescapably subjective judgments, as individuals or offices may be referred to with the nickname by some publications or public figures, while not by others. A more limited (though no less subjective) definition of the term would encompass only those officials appointed without Senate confirmation.