Ambassadors of the United States are persons nominated by the president to serve as the United States' diplomatic representatives to foreign nations, international organizations, and as ambassadors-at-large. Under Article II, Section 2 of the U.S. Constitution, their appointment must be confirmed by the United States Senate; while an ambassador may be appointed during a recess, they can serve only until the end of the next session of Congress, unless subsequently confirmed. Ambassadors are the highest-ranking diplomats of the U.S. and are usually based at the embassy in the host country. They are under the jurisdiction of the Department of State and answer directly to the secretary of state; however, ambassadors serve "at the pleasure of the President", meaning they can be dismissed at any time. Appointments change regularly for various reasons, such as reassignment or retirement. An ambassador may be a career Foreign Service Officer (career diplomat – CD) or a political appointee (PA). In most cases, career foreign service officers serve a tour of approximately three years per ambassadorship, whereas political appointees customarily tender their resignations upon the inauguration of a new president. The State Department publishes a monthly list of ambassadors. A listing by country of past chiefs of mission is maintained by the Office of the Historian of the U.S. Department of State, along with the names and appointment dates of past and present ambassadors-at-large and mission to international organizations.

Current U.S. ambassadors

Note that the information in this list is subject to change due to regular personnel changes resulting from retirements and reassignments. The State Department posts updated lists of ambassadors approximately monthly, accessible via an interactive menu-based website.

Ambassadors to international organizations

Ambassadors to the United Nations

Current ambassadors from the United States to the United Nations:

Other international organizations

Current ambassadors from the United States to other international organizations:

Ambassadors-at-large

Current ambassadors-at-large from the United States with worldwide responsibility:

Other officials with the rank of ambassador

Officials who were granted the rank of ambassador in their senate confirmations:

Office of the United States Trade Representative

U.S. State Department

Other chiefs of mission

Senior diplomatic representatives of the United States hosted in posts other than embassies. Unlike other consulates, these persons report directly to the Secretary of State.

Special envoys, representatives, and coordinators

These diplomatic officials report directly to the Secretary of State. Many oversee a portfolio not restricted to one nation, often an overall goal, and are not usually subject to Senate confirmation. Unlike the State Department offices and diplomats listed in other sections of this Article, the offices and special envoys/representatives/coordinators listed in this Section are created and staffed by direction of top Federal Executive administrators – primarily U.S. Presidents and Secretaries of State – whose political or organizational management philosophies may not be shared by their successors. As such, many of these positions may go unfilled upon assumption of office by successor Presidential Administrations, with their offices sometimes merged with or subsumed into other offices, or abolished altogether.

Nations without exchange of ambassadors

Notable past ambassadors

Many well-known individuals have served the United States as ambassadors, or in formerly analogous positions such as envoy, including several who also became President of the United States (indicated in boldface below). Some notable ambassadors have included:

Ambassadors killed in office

Eight United States Ambassadors have been killed in office – six of them by armed attack and the other two in plane crashes.

Ambassadors to past countries