22 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Guilford | 1 | 37,017 | 34,001 | 1.45% | 1,039 | 36 | Township |
| Lawrenceburg | 2 | 11,345 | 11,273 | 0% | 473 | 24 | Township |
| Miller | 3 | 10,114 | 9,949 | 0.06% | 394 | 26 | Township |
| Lawrenceburg | 4 | 5,235 | 5,139 | 0.36% | 990 | 5 | City |
| Center | 5 | 5,120 | 5,058 | -0.02% | 476 | 11 | Township |
| Greendale | 6 | 4,574 | 4,606 | -0.15% | 808 | 6 | City |
| Logan | 7 | 3,935 | 3,869 | 0.08% | 221 | 18 | Township |
| Aurora | 8 | 3,524 | 3,476 | 0.26% | 1,070 | 3 | City |
| Harrison | 9 | 3,433 | 3,374 | 0.09% | 202 | 17 | Township |
| Manchester | 10 | 3,339 | 3,292 | -0.03% | 73 | 45 | Township |
| Sparta | 11 | 2,966 | 2,905 | 0.17% | 101 | 29 | Township |
| Clay | 12 | 2,887 | 2,840 | 0.1% | 114 | 25 | Township |
| Kelso | 13 | 2,513 | 2,477 | 0.08% | 98 | 26 | Township |
| Jackson | 14 | 1,754 | 1,729 | 0% | 71 | 25 | Township |
| Dillsboro | 15 | 1,391 | 1,368 | 0.29% | 1,027 | 1 | Town |
| Hogan | 16 | 1,155 | 1,140 | 0% | 75 | 15 | Township |
| York | 17 | 1,139 | 1,123 | 0% | 61 | 19 | Township |
| Moores Hill | 18 | 700 | 678 | 0.57% | 1,628 | 0 | Town |
| St. Leon | 19 | 671 | 661 | 0.3% | 98 | 7 | Town |
| West Harrison | 20 | 332 | 329 | 0% | 1,502 | 0 | Town |
| Caesar Creek | 21 | 271 | 265 | 0% | 23 | 12 | Township |
| Mount Carmel | 22 | 78 | 77 | 0% | 1,773 | 0 | Town |
Guilford is the largest city in Dearborn County, with a population of 37,017.
Mount Carmel is the smallest city in Dearborn County, with a population of 78.
There are 22 cities in Dearborn County, Indiana.