| Election Name: | 1846 Chicago mayoral election |
| Type: | presidential |
| Ongoing: | no |
| Previous Year: | 1845 |
| Next Year: | 1847 |
| Nominee1: | John P. Chapin |
| Party1: | Whig Party (United States) |
| Popular Vote1: | 1,104 |
| Percentage1: | 55.20% |
| Nominee2: | Charles Follansbee |
| Party2: | Democratic Party (United States) |
| Popular Vote2: | 667 |
| Percentage2: | 33.35% |
| Mayor | |
| Nominee3: | Philo Carpenter |
| Party3: | Liberty Party (United States, 1840) |
| Popular Vote3: | 229 |
| Percentage3: | 11.45% |
| Before Election: | Augustus Garrett |
| Before Party: | Democratic Party (United States) |
| After Election: | John Putnam Chapin |
| After Party: | Whig Party (United States) |
In the Chicago mayoral election of 1846, Whig nominee John P. Chapin defeated Democratic nominee Charles Follansbee and Liberty nominee Philo Carpenter by a landslide 22 point margin.
Follansbee, a former Chicago alderman from the 1st ward,[1] failed to garner the support of Irish Democrats, an important constituency for the Democratic Party in Chicago. These voters rejected him because he was a champion of the "Native American Act", which would require a period of 21 years of residency before any immigrant could become a naturalized citizen.[2]
Chapin was also a former alderman from the 1st ward.[1]