22 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Portage | 1 | 94,685 | 94,449 | -0.02% | 2,759 | 34 | Township |
| Portage | 2 | 48,766 | 47,996 | 0.18% | 1,374 | 35 | Township |
| Center | 3 | 47,654 | 46,281 | 0.91% | 1,613 | 30 | Township |
| Portage | 4 | 38,729 | 37,963 | 0.4% | 1,507 | 26 | City |
| Valparaiso | 5 | 35,288 | 34,170 | 0.64% | 2,025 | 17 | City |
| Westchester | 6 | 21,076 | 20,692 | -0.01% | 658 | 32 | Township |
| Chesterton | 7 | 14,750 | 14,273 | 0.65% | 1,568 | 9 | Town |
| Porter | 8 | 9,701 | 9,636 | 0.02% | 216 | 45 | Township |
| Union | 9 | 9,464 | 9,407 | 0.02% | 321 | 29 | Township |
| Boone | 10 | 6,110 | 6,098 | 0.1% | 169 | 36 | Township |
| Jackson | 11 | 5,632 | 5,594 | 0.02% | 208 | 27 | Township |
| Porter | 12 | 5,187 | 5,202 | -0.06% | 842 | 6 | Town |
| Pleasant | 13 | 4,535 | 4,482 | 0.18% | 80 | 57 | Township |
| Morgan | 14 | 4,010 | 3,987 | 0% | 89 | 45 | Township |
| Hebron | 15 | 3,744 | 3,753 | -0.05% | 1,872 | 2 | Town |
| Pine | 16 | 2,448 | 2,449 | -0.16% | 91 | 27 | Township |
| Burns Harbor | 17 | 2,165 | 2,075 | 0.84% | 336 | 6 | Town |
| Kouts | 18 | 2,065 | 2,029 | 0.34% | 1,702 | 1 | Town |
| Ogden Dunes | 19 | 1,169 | 1,181 | -0.26% | 1,573 | 1 | Town |
| Beverly Shores | 20 | 602 | 600 | 0% | 168 | 4 | Town |
| Town of Pines | 21 | 591 | 595 | -0.17% | 262 | 2 | Town |
| Dune Acres | 22 | 230 | 233 | -0.43% | 108 | 2 | Town |
Portage is the largest city in Porter County, with a population of 94,685.
Dune Acres is the smallest city in Porter County, with a population of 230.
There are 22 cities in Porter County, Indiana.