| County | Rank | Change (2020) ↓ | 2025 Pop. | 2020 Pop. |
|---|---|---|---|---|
| Ocean County | 1 | 4.35% | 666,265 | 638,465 |
| Gloucester County | 2 | 3.03% | 311,735 | 302,563 |
| Burlington County | 3 | 2.95% | 475,299 | 461,682 |
| Morris County | 4 | 2.44% | 520,831 | 508,439 |
| Sussex County | 5 | 2.31% | 147,246 | 143,915 |
| Somerset County | 6 | 2.23% | 352,432 | 344,754 |
| Warren County | 7 | 2.22% | 111,950 | 109,520 |
| Camden County | 8 | 1.75% | 532,290 | 523,122 |
| Hunterdon County | 9 | 1.67% | 130,939 | 128,786 |
| Salem County | 10 | 1.32% | 65,700 | 64,841 |
| Bergen County | 11 | 1.3% | 966,128 | 953,690 |
| Middlesex County | 12 | 0.84% | 868,681 | 861,408 |
| Union County | 13 | 0.64% | 577,344 | 573,660 |
| Cumberland County | 14 | 0.37% | 154,284 | 153,719 |
| Atlantic County | 15 | 0.25% | 274,875 | 274,190 |
| Monmouth County | 16 | -0.45% | 639,941 | 642,836 |
| Essex County | 17 | -0.71% | 853,903 | 859,974 |
| Mercer County | 18 | -0.78% | 383,455 | 386,466 |
| Hudson County | 19 | -1.42% | 711,654 | 721,879 |
| Passaic County | 20 | -2.01% | 512,917 | 523,439 |
| Cape May County | 21 | -2.13% | 93,020 | 95,044 |
New Jersey's counties show varied growth patterns from 2020 to 2025. Ocean County leads with 4.35% annualized growth, followed by Gloucester County (3.03%) and Burlington County (2.95%). The largest counties are Bergen County (966,128), Middlesex County (868,681), and Essex County (853,903). Of the 21 counties in New Jersey, 15 are growing while 6 have experienced population decline. Overall, counties averaged 0.96% annualized growth, with total population growing by 0.85% annually.