JWT foyer, Knightsbridge, London

JWT foyer, Knightsbridge, London, originally uploaded by Craig Grobler.

JWT is the current name of the United States largest and world's fourth largest advertising agency. It is one of the key companies of Sir Martin Sorrell's WPP Group and is headquartered in New York.

The company that was to become JWT was originally founded by William James Carlton in 1864.

Carlton's original company was renamed by James Walter Thompson in 1877 to The James Walter Thompson Company, which eventually became J. Walter Thompson.

In 2005, the agency was "relaunched" by dropping the name J. Walter Thompson in exchange for JWT.