38 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Hillsboro | 1 | 2,645 | 2,728 | -0.53% | 1,084 | 2 | City |
| Marion | 2 | 1,874 | 1,921 | -0.43% | 679 | 3 | City |
| Marion | 3 | 1,116 | 1,107 | 0% | 11 | 100 | Township |
| Peabody | 4 | 1,083 | 1,120 | -0.82% | 30 | 36 | Township |
| West Branch | 5 | 991 | 1,015 | -0.9% | 28 | 36 | Township |
| Peabody | 6 | 905 | 937 | -0.55% | 715 | 1 | City |
| Marion | 7 | 902 | 840 | 1.35% | 13 | 71 | Township |
| Goessel | 8 | 549 | 557 | -0.18% | 1,449 | 0 | City |
| Centre | 9 | 464 | 470 | -0.64% | 9 | 49 | Township |
| Clear Creek | 10 | 438 | 444 | -0.68% | 6 | 76 | Township |
| Marion | 11 | 397 | 414 | -0.5% | 11 | 36 | Township |
| Florence | 12 | 376 | 390 | -0.53% | 491 | 1 | City |
| Menno | 13 | 322 | 325 | -0.31% | 9 | 36 | Township |
| Lehigh | 14 | 314 | 314 | -0.32% | 9 | 36 | Township |
| Gale | 15 | 242 | 243 | -0.41% | 9 | 27 | Township |
| Burns | 16 | 229 | 235 | -0.43% | 666 | 0 | City |
| Marion | 17 | 223 | 219 | 0.45% | 13 | 18 | Township |
| Risley | 18 | 215 | 214 | 0% | 6 | 34 | Township |
| Durham Park | 19 | 212 | 210 | 0.47% | 6 | 35 | Township |
| East Branch | 20 | 185 | 181 | 0.54% | 5 | 35 | Township |
| Catlin | 21 | 178 | 183 | -1.11% | 5 | 36 | Township |
| Lincolnville | 22 | 169 | 168 | 0% | 751 | 0 | City |
| Blaine | 23 | 166 | 171 | -0.6% | 5 | 36 | Township |
| Colfax | 24 | 164 | 168 | -1.2% | 5 | 36 | Township |
| Lost Springs | 25 | 161 | 165 | -1.23% | 4 | 36 | Township |
| Lehigh | 26 | 160 | 157 | 0.63% | 497 | 0 | City |
| Clark | 27 | 133 | 137 | -1.48% | 4 | 36 | Township |
| Grant | 28 | 120 | 124 | -1.64% | 2 | 67 | Township |
| Tampa | 29 | 104 | 107 | 0% | 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 |
| Moore | 34 | 75 | 74 | -1.32% | 2 | 36 | Township |
| Summit | 35 | 67 | 65 | 1.52% | 2 | 36 | Township |
| Lost Springs | 36 | 56 | 55 | 0% | 252 | 0 | City |
| Doyle | 37 | 37 | 40 | -2.63% | 1 | 38 | Township |
| Durham | 38 | 14 | 14 | 0% | 0.00 | 36 | Township |
Hillsboro is the largest city in Marion County, with a population of 2,645.
Durham is the smallest city in Marion County, with a population of 14.
There are 38 cities in Marion County, Kansas.