The Foreign Service Institute (FSI) is the United States federal government's primary training institution for employees of the U.S. foreign affairs community, preparing American diplomats as well as other professionals to advance U.S. foreign affairs interests overseas and in Washington. FSI provides more than 800 courses—including up to 70 foreign languages—to more than 225,000 enrollees a year from the U.S. Department of State and more than 50 other government agencies and the military service branches. FSI is based at the George P. Shultz National Foreign Affairs Training Center in Arlington, Virginia.

The institute's programs include training for the development of all cadres of the U.S. Department of State, including United States Foreign Service, Civil Service, and Locally Employed staff, who serve at U.S. embassies and consulates overseas as well as in domestic offices. Ranging in length from one day to two years, courses are designed to equip foreign affairs professionals with the knowledge, skills, and attitudes needed to achieve U.S. foreign policy priorities, to promote successful performance in each professional assignment, to assist in navigating international transitions, and to enhance the leadership and management capabilities of the U.S. foreign affairs community. Other courses and resources help family members prepare for the demands of a mobile lifestyle and living abroad, and provide employees and their families with important information about such critical and timely topics as emergency preparedness and cyber-security awareness, among others.

The director of the Foreign Service Institute is equivalent in rank to an Assistant Secretary of State, and is appointed by the secretary of state. The FSI director is the chief learning officer responsible for professional training for the U.S. Department of State and federal foreign affairs agencies.