| Election Name: | 1842 Philadelphia mayoral election |
| Type: | presidential |
| Ongoing: | no |
| Previous Year: | 1841 |
| Next Year: | 1843 |
| Image1: | File:3x4.svg |
| Nominee1: | John Morin Scott |
| Popular Vote1: | 6,145 |
| Percentage1: | 54.80% |
| Nominee2: | Richard Vaux |
| Popular Vote2: | 5,065 |
| Percentage2: | 45.17% |
| Mayor | |
| Before Party: | Whig Party (United States) |
| After Party: | Whig Party (United States) |
The 1842 Philadelphia mayoral election saw the reelection of John Morin Scott.
Beginning in 1839, the city operated under a mixed electoral system. Citizens voted for mayor in a general election. If a candidate receive a majority of the vote, they would be elected mayor. However, if no candidate received a majority, the City Council would select a mayor from the top-two finishers.