Thomas Francis Bayard (October 29, 1828-September 29, 1898) was a member of the United States Senate from Delaware and a member of the Electoral Commission that decided the 1876 Presidential election. As a Democrat, he voted with the seven-member minority on all counts.

He also served as Secretary of State, appointed by President Grover Cleveland in 1885. Upon Cleveland's reelection, Bayard was appointed U.S. ambassador to the United Kingdom, the first person to hold this title (previous representatives to Britain were called "Minister"). His term was controversial, however, after he condemned the American policy of protectionism in trade, which he deemed "state socialism." He died in Massachusetts in 1898.