21 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Fort Wayne | 1 | 277,607 | 264,394 | 0.8% | 2,484 | 112 | City |
| Wayne | 2 | 113,047 | 107,647 | 0.95% | 2,684 | 42 | Township |
| St. Joseph | 3 | 80,765 | 76,488 | 1.03% | 2,298 | 35 | Township |
| Aboite | 4 | 44,627 | 42,174 | 1.07% | 1,343 | 33 | Township |
| Perry | 5 | 39,843 | 37,664 | 1.07% | 1,122 | 36 | Township |
| Adams | 6 | 36,146 | 34,181 | 1.06% | 1,091 | 33 | Township |
| New Haven | 7 | 16,482 | 15,635 | 0.86% | 1,234 | 13 | City |
| Cedar Creek | 8 | 14,502 | 13,711 | 1.07% | 421 | 34 | Township |
| Huntertown | 9 | 11,673 | 11,097 | 0.83% | 1,410 | 8 | Town |
| Springfield | 10 | 4,804 | 4,545 | 1.05% | 136 | 35 | Township |
| Eel River | 11 | 4,442 | 4,205 | 1.05% | 122 | 37 | Township |
| Leo-Cedarville | 12 | 3,823 | 3,636 | 0.82% | 1,027 | 4 | Town |
| Pleasant | 13 | 3,129 | 2,971 | 1% | 89 | 35 | Township |
| Lake | 14 | 2,947 | 2,794 | 1.03% | 83 | 36 | Township |
| Maumee | 15 | 2,789 | 2,641 | 1.01% | 106 | 26 | Township |
| Jefferson | 16 | 2,164 | 2,054 | 0.98% | 59 | 37 | Township |
| Woodburn | 17 | 1,641 | 1,556 | 0.86% | 1,704 | 1 | City |
| Monroeville | 18 | 1,366 | 1,297 | 0.89% | 1,742 | 1 | Town |
| Grabill | 19 | 1,184 | 1,117 | 0.94% | 1,819 | 1 | Town |
| Zanesville | 20 | 600 | 579 | 0.67% | 726 | 1 | Town |
| Jackson | 21 | 530 | 505 | 0.76% | 21 | 25 | Township |
Fort Wayne is the largest city in Allen County, with a population of 277,607.
Jackson is the smallest city in Allen County, with a population of 530.
There are 21 cities in Allen County, Indiana.