United States presidential elections in Pennsylvania occur when voters in the U.S. Commonwealth of Pennsylvania cast ballots for electors to the Electoral College as part of a national election to elect the President and Vice President of the United States.

Voters do not cast ballots directly for a presidential candidate, but rather a slate of electors pledged to support that candidate, with the victorious slate of electors casting their ballots directly for President and Vice President of the United States as part of the Electoral College.

Incumbent Presidents are listed as well as presidential candidates who carried Pennsylvania and runner(s)-up in the state, including major third-party candidates (garnering 5% or more of the popular vote).

The popular vote and percentage margins listed in the "Margin" column are the differences between the total votes received and percentage of the popular vote received by the top two finishers in the corresponding election (i.e. the margin-of-victory of a candidate who carried Pennsylvania over the nearest competitor).

Independent Federalist Democratic-Republican Democratic Whig Republican National Republican Anti-Masonic Know Nothing/American Southern Democratic National Union (1864) Liberal Republican Progressive (1912) Socialist Progressive (1924) American Independent Reform Note: Bold candidate indicates president elected nationally.