15 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Vinton | 1 | 4,971 | 4,925 | 0.18% | 1,018 | 5 | City |
| Belle Plaine | 2 | 2,337 | 2,327 | 0.09% | 735 | 3 | City |
| Atkins | 3 | 2,194 | 2,062 | 1.2% | 2,000 | 1 | City |
| Urbana | 4 | 1,653 | 1,562 | 1.1% | 915 | 2 | City |
| Walford | 5 | 1,355 | 1,364 | -0.15% | 1,303 | 1 | City |
| Shellsburg | 6 | 992 | 964 | 0.51% | 1,256 | 1 | City |
| Newhall | 7 | 889 | 878 | 0.23% | 2,944 | 0 | City |
| Van Horne | 8 | 767 | 771 | -0.13% | 825 | 1 | City |
| Blairstown | 9 | 704 | 708 | -0.14% | 1,419 | 0 | City |
| Keystone | 10 | 620 | 600 | 0.65% | 1,384 | 0 | City |
| Norway | 11 | 462 | 464 | -0.22% | 1,060 | 0 | City |
| Garrison | 12 | 345 | 344 | 0% | 1,120 | 0 | City |
| Mount Auburn | 13 | 162 | 162 | 0% | 659 | 0 | City |
| Luzerne | 14 | 111 | 111 | 0% | 841 | 0 | City |
| Watkins | 15 | 49 | 84 | -9.26% | 118 | 0 | CDP |
Vinton is the largest city in Benton County, with a population of 4,971.
Watkins is the smallest city in Benton County, with a population of 49.
There are 15 cities in Benton County, Iowa.