The Under Secretary of the Treasury for International Affairs is a high-ranking position within United States Department of the Treasury that reports to, advises, and assists the Secretary of the Treasury and the Deputy Secretary of the Treasury on international economic issues and is often referred to as the U.S. Treasury’s top economic diplomat. As of January 13, 2023, the under secretary is Jay Shambaugh.

Jay C. Shambaugh is an American economist who has served as Under Secretary of the Treasury for International Affairs at the U.S. Department of the Treasury since January 2023.