10 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Waterloo | 1 | 67,529 | 67,266 | 0.08% | 1,096 | 62 | City |
| Cedar Falls | 2 | 41,593 | 40,711 | 0.42% | 1,413 | 29 | City |
| Evansdale | 3 | 4,504 | 4,557 | -0.24% | 1,127 | 4 | City |
| Hudson | 4 | 3,008 | 2,545 | 3.16% | 356 | 8 | City |
| La Porte City | 5 | 2,264 | 2,278 | -0.13% | 885 | 3 | City |
| Elk Run Heights | 6 | 1,060 | 1,065 | -0.09% | 978 | 1 | City |
| Dunkerton | 7 | 840 | 838 | 0% | 702 | 1 | City |
| Gilbertville | 8 | 794 | 783 | 0.25% | 2,218 | 0 | City |
| Raymond | 9 | 753 | 758 | -0.13% | 461 | 2 | City |
| Washburn | 10 | 524 | 524 | -4.2% | 424 | 1 | CDP |
Waterloo is the largest city in Black Hawk County, with a population of 67,529.
Washburn is the smallest city in Black Hawk County, with a population of 524.
There are 10 cities in Black Hawk County, Iowa.