22 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Gilead township | 1 | 6,053 | 5,940 | 0.45% | 177 | 34.14 | Township |
| Lexington | 2 | 4,842 | 4,852 | -0.04% | 1,189 | 4.07 | Village |
| Mount Gilead | 3 | 3,553 | 3,502 | 0.28% | 1,049 | 3.39 | Village |
| Bennington township | 4 | 3,322 | 3,281 | 0.36% | 132 | 25.20 | Township |
| Cardington township | 5 | 3,147 | 3,065 | 0.74% | 132 | 23.86 | Township |
| Fulton township | 6 | 3,137 | 3,138 | 0.13% | 109 | 28.68 | Township |
| Congress township | 7 | 2,986 | 2,937 | 0.5% | 95 | 31.39 | Township |
| Harmony township | 8 | 2,628 | 2,596 | 0.38% | 110 | 23.91 | Township |
| Lincoln township | 9 | 2,149 | 2,012 | 1.32% | 94 | 22.89 | Township |
| Cardington | 10 | 2,114 | 2,081 | 0.33% | 1,054 | 2.01 | Village |
| South Bloomfield township | 11 | 1,896 | 1,777 | 1.34% | 73 | 25.89 | Township |
| Peru township | 12 | 1,531 | 1,505 | 0.46% | 65 | 23.38 | Township |
| Westfield township | 13 | 1,440 | 1,239 | 3% | 53 | 26.99 | Township |
| Washington township | 14 | 1,249 | 1,241 | 0.24% | 56 | 22.22 | Township |
| Candlewood Lake | 15 | 1,189 | 783 | 0.17% | 515 | 2.31 | CDP |
| Canaan township | 16 | 910 | 905 | 0.22% | 33 | 27.45 | Township |
| Iberia | 17 | 500 | 624 | 0.81% | 130 | 3.85 | CDP |
| Edison | 18 | 455 | 420 | 1.56% | 1,585 | 0.29 | Village |
| Marengo | 19 | 280 | 280 | 0% | 1,667 | 0.17 | Village |
| Fulton | 20 | 249 | 249 | 0% | 1,518 | 0.16 | Village |
| Chesterville | 21 | 195 | 194 | 0% | 951 | 0.20 | Village |
| Sparta | 22 | 123 | 122 | 0% | 1,414 | 0.09 | Village |
Gilead township is the largest city in Morrow County, with a population of 6,053.
Sparta is the smallest city in Morrow County.
There are 22 cities in Morrow County, Ohio.