40 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Hillsboro | 1 | 2,659 | 2,728 | -0.52% | 1,090 | 2 | City |
| Marion | 2 | 1,882 | 1,921 | -0.42% | 682 | 3 | City |
| Marion | 3 | 1,116 | 1,107 | 0% | 11 | 100 | Township |
| Peabody | 4 | 1,092 | 1,120 | -0.82% | 30 | 36 | Township |
| West Branch | 5 | 1,000 | 1,015 | -0.89% | 28 | 36 | Township |
| Peabody | 6 | 910 | 937 | -0.66% | 719 | 1 | City |
| Marion | 7 | 890 | 840 | 1.37% | 13 | 71 | Township |
| Goessel | 8 | 550 | 557 | -0.36% | 1,451 | 0 | City |
| Centre | 9 | 467 | 470 | -0.64% | 10 | 49 | Township |
| Clear Creek | 10 | 441 | 444 | -0.68% | 6 | 76 | Township |
| Marion | 11 | 399 | 414 | -0.5% | 11 | 36 | Township |
| Florence | 12 | 378 | 390 | -0.79% | 493 | 1 | City |
| Menno | 13 | 323 | 325 | -0.31% | 9 | 36 | Township |
| Lehigh | 14 | 315 | 314 | -0.32% | 9 | 36 | Township |
| Gale | 15 | 243 | 243 | -0.41% | 9 | 27 | Township |
| Burns | 16 | 230 | 235 | -0.43% | 669 | 0 | City |
| Marion | 17 | 222 | 219 | 0.45% | 13 | 18 | Township |
| Risley | 18 | 215 | 214 | 0% | 6 | 34 | Township |
| Durham Park | 19 | 211 | 210 | 0.48% | 6 | 35 | Township |
| East Branch | 20 | 184 | 181 | 0.55% | 5 | 35 | Township |
| Catlin | 21 | 180 | 183 | -1.1% | 5 | 36 | Township |
| Lincolnville | 22 | 169 | 168 | 0% | 751 | 0 | City |
| Blaine | 23 | 167 | 171 | -0.6% | 5 | 36 | Township |
| Colfax | 24 | 166 | 168 | -1.19% | 5 | 36 | Township |
| Lost Springs | 25 | 163 | 165 | -1.21% | 5 | 36 | Township |
| Lehigh | 26 | 159 | 157 | 0% | 494 | 0 | City |
| Clark | 27 | 135 | 137 | -1.46% | 4 | 36 | Township |
| Grant | 28 | 122 | 124 | -1.61% | 2 | 67 | Township |
| Tampa | 29 | 104 | 107 | -0.95% | 584 | 0 | City |
| Marion | 30 | 98 | 98 | 0% | 3 | 35 | Township |
| Fairplay | 31 | 94 | 93 | 0% | 2 | 45 | Township |
| Durham | 32 | 88 | 88 | 0% | 506 | 0 | City |
| Ramona | 33 | 79 | 79 | 0% | 271 | 0 | City |
| Pilsen | 34 | 78 | 77 | 8.33% | 56 | 1 | CDP |
| Moore | 35 | 76 | 74 | -1.3% | 2 | 36 | Township |
| Summit | 36 | 66 | 65 | 1.54% | 2 | 36 | Township |
| Lost Springs | 37 | 56 | 55 | 0% | 252 | 0 | City |
| Doyle | 38 | 38 | 40 | -2.56% | 1 | 38 | Township |
| Eastshore | 39 | 21 | 26 | 5% | 22 | 1 | CDP |
| Durham | 40 | 14 | 14 | 0% | 0.00 | 36 | Township |
Hillsboro is the largest city in Marion County, with a population of 2,659.
Durham is the smallest city in Marion County, with a population of 14.
There are 40 cities in Marion County, Kansas.