The Department of the Treasury is an executive department and the treasury of the United States federal government. It was established by an Act of Congress in 1789 to manage government revenue. The Department is administered by the Secretary of the Treasury, who is a member of the Cabinet.

The first Secretary of the Treasury was Alexander Hamilton, who was sworn into office on September 11, 1789. Hamilton was asked by President George Washington to serve after first having asked Robert Morris (who declined, recommending Hamilton instead). Hamilton almost single-handedly worked out the nation's early financial system, and for several years was a major presence in Washington's administration as well. His portrait is on the obverse of the U.S. ten-dollar bill and the Treasury Department building is shown on the reverse.

Besides the Secretary, one of the best-known Treasury officials is the Treasurer of the United States, who receives and keeps the money of the United States. Facsimile signatures of the Secretary and the Treasurer appear on all modern United States currency.