| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Pekin | 1 | 31,158 | 31,801 | -0.38% | 1,949 | 16 | City |
| East Peoria | 2 | 21,989 | 22,450 | -0.45% | 1,063 | 21 | City |
| Morton | 3 | 17,660 | 17,172 | 0.54% | 1,377 | 13 | Village |
| Washington | 4 | 15,852 | 16,069 | -0.31% | 1,854 | 9 | City |
| Creve Coeur | 5 | 4,791 | 4,920 | -0.52% | 1,132 | 4 | Village |
| Marquette Heights | 6 | 2,473 | 2,537 | -0.48% | 2,539 | 1 | City |
| Tremont | 7 | 2,236 | 2,268 | -0.31% | 1,873 | 1 | Village |
| Mackinaw | 8 | 1,843 | 1,875 | -0.43% | 1,535 | 1 | Village |
| Delavan | 9 | 1,541 | 1,573 | -0.45% | 1,069 | 1 | City |
| North Pekin | 10 | 1,439 | 1,480 | -0.55% | 1,047 | 1 | Village |
| Minier | 11 | 1,133 | 1,154 | -0.44% | 1,970 | 1 | Village |
| South Pekin | 12 | 958 | 987 | -0.62% | 1,860 | 1 | Village |
| Hopedale | 13 | 802 | 819 | -0.5% | 902 | 1 | Village |
| Deer Creek | 14 | 645 | 662 | -0.62% | 1,206 | 1 | Village |
| Green Valley | 15 | 600 | 621 | -0.66% | 1,993 | 0 | Village |
| Bay View Gardens | 16 | 348 | 353 | -0.29% | 612 | 1 | Village |
| Armington | 17 | 301 | 310 | -0.66% | 1,056 | 0 | Village |
Pekin is the largest city in Tazewell County, with a population of 31,158.
Armington is the smallest city in Tazewell County, with a population of 301.
There are 17 cities in Tazewell County, Illinois.