84 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Washington | 1 | 50,071 | 48,674 | 0.63% | 2,346 | 21 | Township |
| Washington | 2 | 50,071 | 48,717 | 0.63% | 2,346 | 21 | Township |
| Washington | 3 | 18,394 | 18,198 | 0.16% | 413 | 45 | Township |
| Washington | 4 | 18,394 | 18,153 | 0.16% | 413 | 45 | Township |
| Phillipsburg | 5 | 15,448 | 15,233 | 0.36% | 4,841 | 3 | Town |
| Phillipsburg | 6 | 15,448 | 15,205 | 0.36% | 4,841 | 3 | Town |
| Phillipsburg | 7 | 15,440 | 15,233 | 0.31% | 4,839 | 3 | Town |
| Phillipsburg | 8 | 15,440 | 15,205 | 0.31% | 4,839 | 3 | Town |
| Hackettstown | 9 | 10,220 | 10,248 | 0.37% | 2,829 | 4 | Town |
| Hackettstown | 10 | 10,220 | 10,232 | 0.37% | 2,829 | 4 | Town |
| Hackettstown | 11 | 10,169 | 10,248 | -0.13% | 2,815 | 4 | Town |
| Hackettstown | 12 | 10,169 | 10,232 | -0.13% | 2,815 | 4 | Town |
| Lopatcong | 13 | 9,541 | 8,791 | 0.41% | 1,304 | 7 | Township |
| Lopatcong | 14 | 9,541 | 8,808 | 0.41% | 1,304 | 7 | Township |
| Washington | 15 | 9,522 | 9,292 | 0.9% | 3,225 | 3 | Township |
| Washington | 16 | 9,522 | 9,271 | 0.9% | 3,225 | 3 | Township |
| Mansfield | 17 | 7,993 | 7,779 | 1.32% | 270 | 30 | Township |
| Mansfield | 18 | 7,993 | 7,771 | 1.32% | 270 | 30 | Township |
| Washington | 19 | 7,396 | 7,300 | 0.28% | 3,764 | 2 | Borough |
| Washington | 20 | 7,396 | 7,288 | 0.28% | 3,764 | 2 | Borough |
| Washington | 21 | 7,395 | 7,300 | 0.27% | 3,763 | 2 | Borough |
| Washington | 22 | 7,395 | 7,288 | 0.27% | 3,763 | 2 | Borough |
| Washington | 23 | 7,066 | 6,496 | 2.01% | 393 | 18 | Township |
| Washington | 24 | 7,066 | 6,490 | 2.01% | 393 | 18 | Township |
| Blairstown | 25 | 5,803 | 5,700 | 0.35% | 194 | 30 | Township |
| Blairstown | 26 | 5,803 | 5,693 | 0.35% | 194 | 30 | Township |
| Independence | 27 | 5,772 | 5,469 | 2.14% | 291 | 20 | Township |
| Independence | 28 | 5,772 | 5,460 | 2.14% | 291 | 20 | Township |
| Allamuchy | 29 | 5,491 | 5,335 | 0.29% | 275 | 20 | Township |
| Allamuchy | 30 | 5,491 | 5,347 | 0.29% | 275 | 20 | Township |
| Panther Valley | 31 | 4,871 | 3,937 | 2.16% | 1,633 | 3 | CDP |
| White | 32 | 4,743 | 4,612 | 0.3% | 173 | 27 | Township |
| White | 33 | 4,743 | 4,604 | 0.3% | 173 | 27 | Township |
| Delaware | 34 | 4,598 | 4,557 | 0.13% | 125 | 37 | Township |
| Delaware | 35 | 4,598 | 4,543 | 0.13% | 125 | 37 | Township |
| Pohatcong | 36 | 3,310 | 3,244 | 0.42% | 248 | 13 | Township |
| Pohatcong | 37 | 3,310 | 3,239 | 0.42% | 248 | 13 | Township |
| Knowlton | 38 | 2,948 | 2,892 | 0.31% | 119 | 25 | Township |
| Knowlton | 39 | 2,948 | 2,887 | 0.31% | 119 | 25 | Township |
| Liberty | 40 | 2,706 | 2,671 | 0.22% | 232 | 12 | Township |
| Liberty | 41 | 2,706 | 2,667 | 0.22% | 232 | 12 | Township |
| Belvidere | 42 | 2,553 | 2,518 | 0.31% | 1,762 | 1 | Town |
| Belvidere | 43 | 2,553 | 2,514 | 0.31% | 1,762 | 1 | Town |
| Belvidere | 44 | 2,552 | 2,518 | 0.28% | 1,761 | 1 | Town |
| Belvidere | 45 | 2,552 | 2,514 | 0.28% | 1,761 | 1 | Town |
| Harmony | 46 | 2,550 | 2,495 | 0.47% | 107 | 24 | Township |
| Harmony | 47 | 2,550 | 2,491 | 0.47% | 107 | 24 | Township |
| Oxford | 48 | 2,485 | 2,446 | 0.32% | 417 | 6 | Township |
| Oxford | 49 | 2,485 | 2,442 | 0.32% | 417 | 6 | Township |
| Alpha | 50 | 2,365 | 2,328 | 0.34% | 1,407 | 2 | Borough |
| Alpha | 51 | 2,365 | 2,324 | 0.34% | 1,407 | 2 | Borough |
| Alpha | 52 | 2,364 | 2,328 | 0.3% | 1,406 | 2 | Borough |
| Alpha | 53 | 2,364 | 2,324 | 0.3% | 1,406 | 2 | Borough |
| Frelinghuysen | 54 | 2,253 | 2,202 | 0.49% | 95 | 24 | Township |
| Frelinghuysen | 55 | 2,253 | 2,201 | 0.49% | 95 | 24 | Township |
| Hope | 56 | 1,865 | 1,836 | 0.32% | 103 | 18 | Township |
| Hope | 57 | 1,865 | 1,831 | 0.32% | 103 | 18 | Township |
| Upper Pohatcong | 58 | 1,771 | 1,774 | -0.06% | 2,741 | 1 | CDP |
| Hardwick | 59 | 1,635 | 1,591 | 0.74% | 44 | 38 | Township |
| Hardwick | 60 | 1,635 | 1,591 | 0.74% | 44 | 38 | Township |
| Oxford | 61 | 1,289 | 1,285 | 1.02% | 1,868 | 1 | CDP |
| Brookfield | 62 | 799 | 956 | 1.14% | 959 | 1 | CDP |
| Washington | 63 | 727 | 693 | 1.39% | 7 | 102 | Township |
| Washington | 64 | 727 | 692 | 1.39% | 7 | 102 | Township |
| Lopatcong Overlook | 65 | 714 | 740 | -0.14% | 1,935 | 0 | CDP |
| Vienna | 66 | 712 | 1,018 | -2.47% | 244 | 3 | CDP |
| Stewartsville | 67 | 683 | 549 | 3.48% | 631 | 1 | CDP |
| Johnsonburg | 68 | 562 | 363 | 5.64% | 528 | 1 | CDP |
| Mountain Lake | 69 | 535 | 565 | -0.56% | 475 | 1 | CDP |
| Upper Stewartsville | 70 | 377 | 380 | 3.01% | 1,077 | 0 | CDP |
| Finesville | 71 | 370 | 272 | 3.64% | 175 | 2 | CDP |
| Hainesburg | 72 | 321 | 117 | 7% | 214 | 2 | CDP |
| Great Meadows | 73 | 312 | 264 | 0.32% | 204 | 2 | CDP |
| Harmony | 74 | 301 | 410 | -2.9% | 291 | 1 | CDP |
| Bridgeville | 75 | 295 | 311 | 4.61% | 325 | 1 | CDP |
| Delaware Park | 76 | 255 | 331 | -10.53% | 1,041 | 0 | CDP |
| Hope | 77 | 225 | 153 | 0.9% | 310 | 1 | CDP |
| Blairstown | 78 | 205 | 268 | -9.29% | 489 | 0 | CDP |
| Columbia | 79 | 204 | 143 | -0.97% | 2,040 | 0 | CDP |
| Brainards | 80 | 157 | 189 | -1.88% | 853 | 0 | CDP |
| Allamuchy | 81 | 128 | 114 | 7.56% | 50 | 3 | CDP |
| Delaware | 82 | 119 | 130 | -1.65% | 229 | 1 | CDP |
| Hutchinson | 83 | 110 | 122 | -1.79% | 112 | 1 | CDP |
| Buttzville | 84 | 92 | 57 | -4.17% | 112 | 1 | CDP |
Washington is the largest city in Warren County, with a population of 50,071.
Buttzville is the smallest city in Warren County, with a population of 92.
There are 84 cities in Warren County, New Jersey.