| County | Rank | Change (2020) ↓ | 2025 Pop. | 2020 Pop. |
|---|---|---|---|---|
| Juab County | 1 | 17.58% | 13,897 | 11,819 |
| Tooele County | 2 | 17.57% | 86,243 | 73,355 |
| Iron County | 3 | 17.16% | 67,617 | 57,713 |
| Washington County | 4 | 16.42% | 211,896 | 182,015 |
| Piute County | 5 | 15.56% | 1,664 | 1,440 |
| Kane County | 6 | 15.29% | 8,869 | 7,693 |
| Utah County | 7 | 13.34% | 752,138 | 663,595 |
| Box Elder County | 8 | 12.18% | 65,006 | 57,946 |
| Sanpete County | 9 | 10.25% | 31,449 | 28,526 |
| Cache County | 10 | 9.92% | 146,889 | 133,631 |
| Uintah County | 11 | 9.42% | 39,033 | 35,672 |
| Wasatch County | 12 | 9.08% | 38,238 | 35,055 |
| Rich County | 13 | 8.26% | 2,712 | 2,505 |
| Duchesne County | 14 | 7.78% | 21,147 | 19,620 |
| Morgan County | 15 | 7.62% | 13,326 | 12,382 |
| Sevier County | 16 | 6.46% | 22,946 | 21,554 |
| Garfield County | 17 | 6.33% | 5,426 | 5,103 |
| Weber County | 18 | 5.27% | 276,858 | 262,988 |
| Davis County | 19 | 4.42% | 379,847 | 363,771 |
| Millard County | 20 | 4.33% | 13,625 | 13,060 |
| Emery County | 21 | 4.05% | 10,246 | 9,847 |
| Wayne County | 22 | 2.84% | 2,574 | 2,503 |
| Carbon County | 23 | 1.27% | 20,747 | 20,487 |
| Salt Lake County | 24 | -0.23% | 1,184,301 | 1,186,983 |
| Beaver County | 25 | -0.25% | 7,065 | 7,083 |
| Daggett County | 26 | -0.63% | 946 | 952 |
| Summit County | 27 | -0.71% | 42,187 | 42,489 |
| Grand County | 28 | -1.01% | 9,576 | 9,674 |
| San Juan County | 29 | -1.78% | 14,262 | 14,521 |
Utah's counties show varied growth patterns from 2020 to 2025. Juab County leads with 17.58% annualized growth, followed by Tooele County (17.57%) and Iron County (17.16%). The largest counties are Salt Lake County (1,184,301), Utah County (752,138), and Davis County (379,847). Of the 29 counties in Utah, 23 are growing while 6 have experienced population decline. Overall, counties averaged 7.51% annualized growth, with total population growing by 6.3% annually.