27 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Brigham City | 1 | 20,158 | 19,687 | 0.47% | 820 | 24.58 | City |
| Tremonton | 2 | 14,039 | 9,968 | 6.16% | 1,687 | 8.32 | City |
| Perry | 3 | 6,167 | 5,589 | 1.92% | 772 | 7.99 | City |
| Erda | 4 | 4,347 | 3,071 | 51.41% | 108 | 40.12 | City |
| Erda | 5 | 4,347 | 3,071 | 3.6% | 108 | 40.12 | City |
| Erda | 6 | 4,347 | 3,592 | 51.41% | 108 | 40.12 | City |
| Erda | 7 | 4,347 | 3,592 | 3.6% | 108 | 40.12 | City |
| Erda | 8 | 2,744 | 3,071 | -4.42% | 68 | 40.12 | City |
| Erda | 9 | 2,744 | 3,071 | -34.6% | 68 | 40.12 | City |
| Erda | 10 | 2,744 | 3,592 | -4.42% | 68 | 40.12 | City |
| Erda | 11 | 2,744 | 3,592 | -34.6% | 68 | 40.12 | City |
| Garland | 12 | 2,720 | 2,590 | 0.97% | 1,473 | 1.85 | City |
| Willard | 13 | 2,476 | 1,993 | 4.08% | 445 | 5.57 | City |
| Honeyville | 14 | 1,816 | 1,616 | 2.25% | 155 | 11.73 | City |
| South Willard | 15 | 1,542 | 1,519 | -0.13% | 265 | 5.83 | CDP |
| Mantua | 16 | 1,435 | 1,105 | 4.82% | 294 | 4.88 | Town |
| Riverside | 17 | 1,414 | 1,010 | 3.21% | 211 | 6.69 | CDP |
| Elwood | 18 | 1,346 | 1,181 | 2.51% | 157 | 8.55 | Town |
| Thatcher | 19 | 1,123 | 684 | 2.09% | 94 | 11.97 | CDP |
| Corinne | 20 | 903 | 823 | 1.8% | 239 | 3.79 | City |
| Bear River City | 21 | 886 | 878 | 0.23% | 493 | 1.80 | City |
| Fielding | 22 | 666 | 556 | 3.42% | 1,266 | 0.53 | Town |
| Plymouth | 23 | 446 | 426 | 0.9% | 511 | 0.87 | Town |
| Deweyville | 24 | 444 | 419 | 1.14% | 70 | 6.37 | Town |
| Portage | 25 | 297 | 277 | 1.37% | 116 | 2.56 | Town |
| Howell | 26 | 230 | 235 | -0.43% | 7 | 35.26 | Town |
| Snowville | 27 | 158 | 162 | -0.63% | 102 | 1.55 | Town |
Brigham City is the largest city in Box Elder County, with a population of 20,158.
Snowville is the smallest city in Box Elder County.
There are 27 cities in Box Elder County, Utah.