| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Mansfield | 1 | 47,402 | 47,494 | 0.04% | 1,535 | 31 | City |
| Shelby | 2 | 9,215 | 9,284 | -0.17% | 1,460 | 6 | City |
| Ontario | 3 | 6,689 | 6,690 | -0.04% | 603 | 11 | City |
| Bellville | 4 | 2,022 | 1,962 | 0.45% | 709 | 3 | Village |
| Butler | 5 | 928 | 933 | -0.11% | 719 | 1 | Village |
| Shiloh | 6 | 614 | 618 | -0.16% | 670 | 1 | Village |
| Lucas | 7 | 585 | 589 | -0.17% | 864 | 1 | Village |
Mansfield is the largest city in Richland County, with a population of 47,402.
Lucas is the smallest city in Richland County, with a population of 585.
There are 7 cities in Richland County, Ohio.