40 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Bruno | 1 | 20,006 | 16,881 | 6.05% | 571 | 35 | Township |
| Andover | 2 | 17,508 | 14,967 | 2.99% | 1,681 | 10 | City |
| El Dorado | 3 | 12,674 | 12,771 | -0.16% | 1,324 | 10 | City |
| Augusta | 4 | 9,068 | 9,241 | -0.38% | 2,138 | 4 | City |
| Pleasant | 5 | 5,394 | 5,348 | -0.74% | 150 | 36 | Township |
| Rose Hill | 6 | 4,315 | 4,188 | 0.58% | 1,913 | 2 | City |
| Richland | 7 | 2,589 | 2,583 | -1.11% | 72 | 36 | Township |
| Prospect | 8 | 2,564 | 2,551 | -0.31% | 32 | 79 | Township |
| Towanda | 9 | 2,537 | 2,601 | -1.32% | 71 | 36 | Township |
| Benton | 10 | 2,312 | 2,378 | -1.53% | 64 | 36 | Township |
| Douglass | 11 | 1,935 | 2,007 | -1.68% | 54 | 36 | Township |
| Douglass | 12 | 1,505 | 1,549 | -0.59% | 1,417 | 1 | City |
| Spring | 13 | 1,441 | 1,479 | -1.5% | 40 | 36 | Township |
| Towanda | 14 | 1,419 | 1,443 | -0.35% | 1,553 | 1 | City |
| Augusta | 15 | 1,209 | 1,227 | -1.23% | 38 | 32 | Township |
| Benton | 16 | 930 | 933 | 0.43% | 15 | 60 | Township |
| Benton | 17 | 926 | 944 | -0.43% | 662 | 1 | City |
| Little Walnut | 18 | 918 | 934 | -1.4% | 25 | 36 | Township |
| Whitewater | 19 | 650 | 660 | -0.31% | 1,582 | 0 | City |
| Leon | 20 | 647 | 656 | -0.31% | 895 | 1 | City |
| El Dorado | 21 | 636 | 648 | -1.24% | 12 | 51 | Township |
| Plum Grove | 22 | 573 | 590 | -1.38% | 16 | 36 | Township |
| Rosalia | 23 | 544 | 557 | -1.63% | 9 | 63 | Township |
| Bloomington | 24 | 494 | 491 | -1.2% | 14 | 36 | Township |
| Fairmount | 25 | 465 | 481 | -1.69% | 13 | 36 | Township |
| Potwin | 26 | 411 | 421 | -0.48% | 1,749 | 0 | City |
| Rock Creek | 27 | 291 | 297 | -1.69% | 8 | 36 | Township |
| Chelsea | 28 | 274 | 273 | -0.72% | 3 | 101 | Township |
| Elbing | 29 | 218 | 225 | -0.91% | 1,267 | 0 | City |
| Clifford | 30 | 208 | 212 | -1.89% | 5 | 42 | Township |
| Glencoe | 31 | 170 | 175 | -1.73% | 3 | 62 | Township |
| Rosalia | 32 | 147 | 100 | -1.34% | 116 | 1 | CDP |
| Union | 33 | 137 | 142 | -2.14% | 2 | 62 | Township |
| Cassoday | 34 | 105 | 107 | -0.94% | 309 | 0 | City |
| Latham | 35 | 97 | 99 | -1.02% | 447 | 0 | City |
| Hickory | 36 | 82 | 85 | -1.2% | 1 | 62 | Township |
| Clay | 37 | 67 | 62 | 1.52% | 2 | 36 | Township |
| Beaumont | 38 | 50 | 29 | 6.38% | 90 | 1 | CDP |
| Benton | 39 | 28 | 30 | -3.45% | 1 | 36 | Township |
| Towanda | 40 | 24 | 25 | 0% | 1 | 36 | Township |
Bruno is the largest city in Butler County, with a population of 20,006.
Towanda is the smallest city in Butler County, with a population of 24.
There are 40 cities in Butler County, Kansas.