Rufus King (1755-1827) was an American lawyer, politician, and statesman. He was a delegate for Massachusetts to the Continental Congress and the Constitutional Convention. He represented New York in the United States Senate, served as Ambassador to Great Britain, and was a candidate for both Vice President and President of the United States.

King was born on March 24, 1755 in Scarborough, which was then a part of Massachusetts but is now n the state of Maine. Rufus attended Harvard, but his studies interrupted by the Revolutionary War. He fought in the Battle of Lexington and Concord and the participated in the Siege of Boston. He returned to Harvard after the British withdrew and completed his studies in 1777. He was admitted to the bar, and began a legal practice in Newburyport, Massachusetts. King was first elected to the Massachusetts state assembly in 1783, and returned there each year until 1785. Massachusetts sent him to the Continental Congress under the Articles of Confederation from 1784 to 1787. King opposed the expansion of slavery into the Northwest Territory and proposed that slavery be prohibited in that area. This prohibition became law in the Northwest Ordinance of 1787.

Also in 1787 King was sent to the Constitutional Convention, where he worked closely with Alexander Hamilton on the Committee of Style and Arrangement to prepare the final draft. He returned home and went to work to get the Constitution ratified and to position himself to be named to the U.S. Senate. He was only partially successful. Massachusetts ratified the Constitution, but his efforts to influence the state legislature and get to the Senate were rebuffed.

At Hamilton's urging he moved to New York City and was elected to the New York state legislature in 1788. When the U.S. Constitution took effect, the state senate and house agreed to send Philip Schuyler to the U. S. Senate, but they disagreed on who should serve in the second seat. After several shifts, the upstate and New York City groups were still deadlocked. Governor George Clinton proposed Rufus King as a compromise candidate, and he was elected. He represented New York in the Senate from 1789 to 1796 and from 1813 to 1825.

King also served as the United States ambassador to Great Britain from 1796 to 1803 and in 1825 to 1826. He was the Federalist Party candidate for Vice President of the United States in 1804 and 1808 and for President of the United States in 1816.