| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Bryan | 1 | 8,553 | 8,722 | -0.3% | 1,584 | 5 | City |
| Montpelier | 2 | 3,869 | 3,936 | -0.39% | 1,346 | 3 | Village |
| Edgerton | 3 | 1,881 | 1,880 | -0.05% | 1,097 | 2 | Village |
| West Unity | 4 | 1,729 | 1,755 | -0.35% | 1,123 | 2 | Village |
| Pioneer | 5 | 1,414 | 1,435 | -0.35% | 693 | 2 | Village |
| Stryker | 6 | 1,234 | 1,260 | -0.4% | 1,379 | 1 | Village |
| Edon | 7 | 783 | 786 | -0.13% | 714 | 1 | Village |
| Blakeslee | 8 | 104 | 107 | -0.95% | 1,106 | 0 | Village |
| Holiday City | 9 | 46 | 48 | -2.13% | 18 | 3 | Village |
Bryan is the largest city in Williams County, with a population of 8,553.
Holiday City is the smallest city in Williams County, with a population of 46.
There are 9 cities in Williams County, Ohio.