This is a list of United States ambassadors to Mongolia.

The United States established diplomatic relations with then-People's Republic of Mongolia on January 27, 1987.

The embassy in Ulaanbaatar was opened Apr 17, 1988, with Steven Mann as Chargé d'Affaires ad interim.

Richard Llewellyn Williams was the first ambassador to the Republic, and resided in the District of Columbia.

The U.S. maintains its embassy in Ulaanbaatar.