27 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Brigham City | 1 | 20,478 | 19,683 | 0.78% | 833 | 25 | City |
| Tremonton | 2 | 13,354 | 9,968 | 5.34% | 1,604 | 8 | City |
| Perry | 3 | 6,241 | 5,589 | 2.13% | 781 | 8 | City |
| Erda | 4 | 4,150 | 3,071 | 44.55% | 103 | 40 | City |
| Erda | 5 | 4,150 | 3,071 | 2.85% | 103 | 40 | City |
| Erda | 6 | 4,150 | 3,574 | 44.55% | 103 | 40 | City |
| Erda | 7 | 4,150 | 3,574 | 2.85% | 103 | 40 | City |
| Garland | 8 | 2,817 | 2,592 | 1.62% | 1,525 | 2 | City |
| Erda | 9 | 2,744 | 3,071 | -4.42% | 68 | 40 | City |
| Erda | 10 | 2,744 | 3,071 | -32% | 68 | 40 | City |
| Erda | 11 | 2,744 | 3,574 | -4.42% | 68 | 40 | City |
| Erda | 12 | 2,744 | 3,574 | -32% | 68 | 40 | City |
| Willard | 13 | 2,443 | 2,003 | 3.74% | 439 | 6 | City |
| Honeyville | 14 | 1,824 | 1,616 | 2.3% | 156 | 12 | City |
| South Willard | 15 | 1,542 | 1,519 | -0.13% | 265 | 6 | CDP |
| Mantua | 16 | 1,414 | 1,112 | 4.43% | 290 | 5 | Town |
| Riverside | 17 | 1,414 | 1,010 | 3.21% | 211 | 7 | CDP |
| Elwood | 18 | 1,370 | 1,182 | 2.78% | 160 | 9 | Town |
| Thatcher | 19 | 1,123 | 684 | 2.09% | 94 | 12 | CDP |
| Bear River City | 20 | 907 | 877 | 0.67% | 505 | 2 | City |
| Corinne | 21 | 892 | 825 | 1.48% | 236 | 4 | City |
| Fielding | 22 | 649 | 558 | 2.85% | 1,234 | 1 | Town |
| Plymouth | 23 | 508 | 427 | 3.25% | 583 | 1 | Town |
| Deweyville | 24 | 463 | 420 | 1.76% | 73 | 6 | Town |
| Portage | 25 | 295 | 277 | 1.03% | 115 | 3 | Town |
| Howell | 26 | 237 | 237 | 0% | 7 | 35 | Town |
| Snowville | 27 | 164 | 162 | 0% | 106 | 2 | Town |
Brigham City is the largest city in Box Elder County, with a population of 20,478.
Snowville is the smallest city in Box Elder County, with a population of 164.
There are 27 cities in Box Elder County, Utah.