18 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Pekin | 1 | 30,987 | 31,823 | -0.45% | 1,938 | 16 | City |
| East Peoria | 2 | 21,814 | 22,443 | -0.48% | 1,055 | 21 | City |
| Morton | 3 | 17,746 | 17,178 | 0.54% | 1,384 | 13 | Village |
| Washington | 4 | 15,753 | 16,064 | -0.33% | 1,842 | 9 | City |
| Creve Coeur | 5 | 4,784 | 4,927 | -0.5% | 1,131 | 4 | Village |
| Marquette Heights | 6 | 2,459 | 2,536 | -0.53% | 2,525 | 1 | City |
| Tremont | 7 | 2,233 | 2,274 | -0.31% | 1,870 | 1 | Village |
| Mackinaw | 8 | 1,831 | 1,882 | -0.44% | 1,525 | 1 | Village |
| Delavan | 9 | 1,530 | 1,574 | -0.46% | 1,061 | 1 | City |
| North Pekin | 10 | 1,422 | 1,473 | -0.56% | 1,035 | 1 | Village |
| Minier | 11 | 1,127 | 1,156 | -0.44% | 1,960 | 1 | Village |
| South Pekin | 12 | 954 | 987 | -0.52% | 1,852 | 1 | Village |
| Hopedale | 13 | 794 | 817 | -0.5% | 893 | 1 | Village |
| Deer Creek | 14 | 643 | 663 | -0.46% | 1,202 | 1 | Village |
| Green Valley | 15 | 590 | 616 | -0.67% | 1,960 | 0 | Village |
| Spring Bay | 16 | 491 | 466 | 0.82% | 714 | 1 | Village |
| Bay View Gardens | 17 | 352 | 355 | 0% | 619 | 1 | Village |
| Armington | 18 | 300 | 311 | -0.66% | 1,053 | 0 | Village |
Pekin is the largest city in Tazewell County, with a population of 30,987.
Armington is the smallest city in Tazewell County, with a population of 300.
There are 18 cities in Tazewell County, Illinois.