Rufus King (March 24, 1755April 29, 1827) was an American lawyer, politician, and diplomat. He was a delegate for Massachusetts to the Continental Congress and the Philadelphia Convention and was one of the signers of the United States Constitution in 1787. After formation of the new Congress he represented New York in the United States Senate. He emerged as a leading member of the Federalist Party, serving as the party's last presidential nominee in the 1816 presidential election.