Embassy of the United States of America | London

33 Nine Elms Lane
London SW11 7US 
United Kingdom

https://uk.usembassy.gov/embassy-consulates/london/ 

The U.S. Embassy in London, United Kingdom, was established in 1785 and is one of the oldest and most important diplomatic missions of the United States. The current Ambassador, Jane D. Hartley, leads the mission to strengthen further the deep and historic ties between the United States and the United Kingdom.

The Embassy provides various services, including consular assistance to U.S. citizens and visa services to British nationals and other foreign nationals wishing to travel to the United States. It also promotes numerous programs and initiatives in the areas of education, culture, and trade to enhance transatlantic exchange.
 

In addition to the Embassy in London, there is an important U.S. Consulate in Scotland:
The U.S. Consulate in Edinburgh offers various consular services, including assistance for U.S. citizens and visa processing. It is crucial in fostering bilateral relations between the United States and Scotland, supporting cultural and economic initiatives, and promoting educational, scientific, and technological exchanges.

U.S. Consulate General in Edinburgh

3 Regent Terrace
Edinburgh EH7 5BW
Phone: [44] (0)131-556-8315

https://uk.usembassy.gov/embassy-consulates/edinburgh/