The 1820 United States presidential election was the ninth quadrennial presidential election. It was held from Wednesday, November 1, to Wednesday, December 6, 1820. Taking place at the height of the Era of Good Feelings, the election saw incumbent Democratic-Republican President James Monroe win re-election without a major opponent. It was the third and the most recent United States presidential election in which a presidential candidate ran effectively unopposed. As of 2024, this is the most recent presidential election where an incumbent president was re-elected who was neither a Democrat nor a Republican, before the Democratic-Republican party split into separate parties.

The Era of Good Feelings marked a period in the political history of the United States that reflected a sense of national purpose and a desire for unity among Americans in the aftermath of the War of 1812. The era saw the collapse of the Federalist Party and an end to the bitter partisan disputes between it and the dominant Democratic-Republican Party during the First Party System. President James Monroe strove to downplay partisan affiliation in making his nominations, with the ultimate goal of national unity and eliminating political parties altogether from national politics. The period is so closely associated with Monroe's presidency (1817–1825) and his administrative goals that his name and the era are virtually synonymous.