10 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Macomb | 1 | 14,647 | 15,000 | -0.4% | 1,351 | 11 | City |
| Bushnell | 2 | 2,620 | 2,706 | -0.53% | 1,238 | 2 | City |
| Colchester | 3 | 1,070 | 1,105 | -0.56% | 930 | 1 | City |
| Blandinsville | 4 | 544 | 562 | -0.55% | 622 | 1 | Village |
| Prairie City | 5 | 395 | 407 | -0.5% | 392 | 1 | Village |
| Industry | 6 | 383 | 395 | -0.52% | 833 | 0 | Village |
| Good Hope | 7 | 349 | 360 | -0.57% | 1,163 | 0 | Village |
| Bardolph | 8 | 202 | 207 | -0.49% | 327 | 1 | Village |
| Tennessee | 9 | 100 | 100 | 0% | 235 | 0 | Village |
| Sciota | 10 | 35 | 37 | 0% | 112 | 0 | Village |
Macomb is the largest city in McDonough County, with a population of 14,647.
Sciota is the smallest city in McDonough County, with a population of 35.
There are 10 cities in McDonough County, Illinois.