| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Huber Heights | 1 | 43,964 | 43,415 | 0.13% | 1,940 | 23 | City |
| Urbana | 2 | 11,123 | 11,182 | -0.15% | 1,337 | 8 | City |
| St. Paris | 3 | 1,883 | 1,885 | -0.05% | 1,162 | 2 | Village |
| Mechanicsburg | 4 | 1,680 | 1,678 | -0.06% | 1,713 | 1 | Village |
| North Lewisburg | 5 | 1,659 | 1,642 | 0.12% | 1,545 | 1 | Village |
| Christiansburg | 6 | 501 | 508 | -0.4% | 2,105 | 0 | Village |
| Woodstock | 7 | 283 | 287 | -0.35% | 1,000 | 0 | Village |
| Mutual | 8 | 127 | 127 | 0% | 941 | 0 | Village |
Huber Heights is the largest city in Champaign County, with a population of 43,964.
Mutual is the smallest city in Champaign County, with a population of 127.
There are 8 cities in Champaign County, Ohio.