| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Jacksonville | 1 | 17,644 | 18,242 | -0.61% | 1,670 | 11 | City |
| South Jacksonville | 2 | 3,172 | 3,294 | -0.72% | 1,402 | 2 | Village |
| Waverly | 3 | 1,132 | 1,187 | -0.88% | 1,093 | 1 | City |
| Meredosia | 4 | 789 | 819 | -0.75% | 913 | 1 | Village |
| Franklin | 5 | 582 | 609 | -0.85% | 702 | 1 | Village |
| Murrayville | 6 | 542 | 564 | -0.73% | 1,093 | 0 | Village |
| Woodson | 7 | 479 | 498 | -0.83% | 1,216 | 0 | Village |
| Chapin | 8 | 453 | 475 | -0.88% | 454 | 1 | Village |
| Curran | 9 | 207 | 212 | -0.96% | 105 | 2 | Village |
| Concord | 10 | 149 | 155 | -0.67% | 598 | 0 | Village |
| Berlin | 11 | 143 | 146 | -0.69% | 160 | 1 | Village |
| Glasgow | 12 | 107 | 112 | -0.93% | 106 | 1 | Village |
| Naples | 13 | 93 | 98 | -1.06% | 154 | 1 | Town |
| Lynnville | 14 | 92 | 96 | -1.08% | 1,195 | 0 | Village |
| Exeter | 15 | 82 | 86 | -1.2% | 119 | 1 | Village |
Jacksonville is the largest city in Morgan County, with a population of 17,644.
Exeter is the smallest city in Morgan County, with a population of 82.
There are 15 cities in Morgan County, Illinois.