The 1840 United States presidential election was the 14th quadrennial presidential election, held from Friday, October 30 to Wednesday, December 2, 1840. Economic recovery from the Panic of 1837 was incomplete, and Whig nominee William Henry Harrison defeated incumbent President Martin Van Buren of the Democratic Party. The election marked the first of two Whig victories in presidential elections, but was the only one where they won a majority of the popular vote. This was the third rematch in American history, which would not occur again until 1892.

The election of the president and the vice president of the United States is an indirect election in which citizens of the United States who are registered to vote in one of the fifty U.S. states or in Washington, D.C., cast ballots not directly for those offices, but instead for members of the Electoral College. These electors then cast direct votes, known as electoral votes, for president, and for vice president. The candidate who receives an absolute majority of electoral votes is then elected to that office. If no candidate receives an absolute majority of the votes for president, the House of Representatives elects the president; likewise if no one receives an absolute majority of the votes for vice president, then the Senate elects the vice president.