A Foreign Service officer (FSO) is a commissioned member of the United States Foreign Service. FSOs formulate and implement the foreign policy of the United States. They spend most of their careers overseas as members of U.S. embassies, consulates, and other diplomatic missions, though some receive assignments to serve at combatant commands, Congress, and educational institutions such as the various U.S. service academies.
As of 2021, there were over 8,000 FSOs.