| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Independence | 1 | 6,356 | 6,079 | 0.7% | 1,054 | 6 | City |
| Jesup | 2 | 2,563 | 2,517 | 0.23% | 1,392 | 2 | City |
| Fairbank | 3 | 1,150 | 1,109 | 0.44% | 1,565 | 1 | City |
| Winthrop | 4 | 820 | 825 | -0.36% | 1,037 | 1 | City |
| Hazleton | 5 | 713 | 709 | -0.14% | 892 | 1 | City |
| Quasqueton | 6 | 595 | 575 | 0.34% | 527 | 1 | City |
| Lamont | 7 | 431 | 433 | -0.23% | 737 | 1 | City |
| Brandon | 8 | 323 | 328 | -0.62% | 997 | 0 | City |
| Rowley | 9 | 266 | 269 | -0.37% | 686 | 0 | City |
| Aurora | 10 | 166 | 167 | -0.6% | 314 | 1 | City |
| Stanley | 11 | 87 | 87 | 0% | 429 | 0 | City |
Independence is the largest city in Buchanan County, with a population of 6,356.
Stanley is the smallest city in Buchanan County, with a population of 87.
There are 11 cities in Buchanan County, Iowa.