11 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Macomb | 1 | 14,761 | 14,981 | -0.3% | 1,392 | 10.60 | City |
| Bushnell | 2 | 2,651 | 2,705 | -0.41% | 1,252 | 2.12 | City |
| Colchester | 3 | 1,080 | 1,104 | -0.46% | 939 | 1.15 | City |
| Blandinsville | 4 | 551 | 563 | -0.36% | 630 | 0.88 | Village |
| Prairie City | 5 | 398 | 407 | -0.5% | 395 | 1.01 | Village |
| Industry | 6 | 386 | 395 | -0.52% | 839 | 0.46 | Village |
| Good Hope | 7 | 352 | 361 | -0.56% | 1,173 | 0.30 | Village |
| Adair | 8 | 256 | 179 | 1.19% | 595 | 0.43 | CDP |
| Bardolph | 9 | 204 | 208 | -0.49% | 331 | 0.62 | Village |
| Tennessee | 10 | 97 | 99 | 0% | 228 | 0.42 | Village |
| Sciota | 11 | 37 | 37 | 0% | 119 | 0.31 | Village |
Macomb is the largest city in McDonough County, with a population of 14,761.
Sciota is the smallest city in McDonough County.
There are 11 cities in McDonough County, Illinois.