| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Cairo | 1 | 1,467 | 1,717 | -3.17% | 210 | 7 | City |
| Tamms | 2 | 362 | 420 | -2.95% | 155 | 2 | Village |
| East Cape Girardeau | 3 | 243 | 284 | -3.19% | 124 | 2 | Village |
| McClure | 4 | 216 | 253 | -3.14% | 141 | 2 | Village |
| Thebes | 5 | 175 | 205 | -3.31% | 100 | 2 | Village |
Cairo is the largest city in Alexander County, with a population of 1,467.
Thebes is the smallest city in Alexander County, with a population of 175.
There are 5 cities in Alexander County, Illinois.