The United States secretary of transportation is the head of the United States Department of Transportation. The secretary serves as the principal advisor to the President of the United States on all matters relating to transportation. The secretary is a statutory member of the Cabinet of the United States, and is fourteenth in the presidential line of succession.

The United States Department of Transportation is one of the executive departments of the U.S. federal government. It is headed by the secretary of transportation, who reports directly to the president of the United States and is a member of the president's Cabinet.