78 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Edison township | 1 | 106,512 | 107,066 | -0.15% | 3,541 | 30.08 | Township |
| Woodbridge township | 2 | 103,168 | 103,656 | -0.01% | 4,436 | 23.26 | Township |
| Old Bridge township | 3 | 68,947 | 66,744 | 0.57% | 1,806 | 38.18 | Township |
| Piscataway township | 4 | 61,744 | 60,742 | 0.65% | 3,285 | 18.79 | Township |
| New Brunswick | 5 | 56,218 | 55,288 | 0.33% | 10,743 | 5.23 | City |
| New Brunswick city | 6 | 55,848 | 55,288 | 0% | 10,672 | 5.23 | City |
| Perth Amboy city | 7 | 55,331 | 55,383 | 0.07% | 11,869 | 4.66 | City |
| Perth Amboy | 8 | 55,159 | 55,383 | -0.08% | 11,832 | 4.66 | City |
| East Brunswick township | 9 | 49,995 | 49,559 | 0.55% | 2,295 | 21.78 | Township |
| Monroe township | 10 | 49,138 | 48,493 | 0.58% | 1,172 | 41.94 | Township |
| South Brunswick township | 11 | 46,621 | 46,896 | 0.06% | 1,148 | 40.61 | Township |
| Sayreville borough | 12 | 46,210 | 45,225 | 0.78% | 2,919 | 15.83 | Borough |
| Sayreville | 13 | 45,676 | 45,225 | 0.2% | 2,885 | 15.83 | Borough |
| North Brunswick township | 14 | 44,180 | 43,774 | 0.08% | 3,672 | 12.03 | Township |
| Old Bridge | 15 | 29,179 | 27,836 | 1.25% | 3,707 | 7.87 | CDP |
| Carteret borough | 16 | 25,633 | 25,297 | 0.69% | 5,838 | 4.39 | Borough |
| Carteret | 17 | 25,270 | 25,297 | -0.02% | 5,755 | 4.39 | Borough |
| South Plainfield borough | 18 | 24,103 | 24,286 | -0.06% | 2,905 | 8.30 | Borough |
| South Plainfield | 19 | 24,027 | 24,286 | -0.22% | 2,896 | 8.30 | Borough |
| Plainsboro township | 20 | 23,898 | 24,021 | 0.05% | 2,032 | 11.76 | Township |
| North Plainfield | 21 | 22,444 | 22,748 | -0.27% | 7,996 | 2.81 | Borough |
| Woodbridge | 22 | 21,342 | 20,500 | 0.65% | 4,635 | 4.61 | CDP |
| Colonia | 23 | 18,778 | 17,782 | 0.35% | 4,660 | 4.03 | CDP |
| Iselin | 24 | 18,465 | 17,356 | -0.08% | 5,858 | 3.15 | CDP |
| Avenel | 25 | 17,261 | 17,175 | 0.1% | 5,074 | 3.40 | CDP |
| South River borough | 26 | 15,959 | 16,051 | 0.09% | 5,730 | 2.79 | Borough |
| South River | 27 | 15,851 | 16,051 | -0.25% | 5,692 | 2.79 | Borough |
| Metuchen borough | 28 | 15,053 | 15,048 | 0.25% | 5,306 | 2.84 | Borough |
| Highland Park borough | 29 | 14,983 | 15,033 | 0.08% | 8,228 | 1.82 | Borough |
| Metuchen | 30 | 14,929 | 15,048 | -0.16% | 5,262 | 2.84 | Borough |
| Highland Park | 31 | 14,909 | 15,033 | -0.17% | 8,187 | 1.82 | Borough |
| Middlesex borough | 32 | 14,471 | 14,593 | 0.03% | 4,149 | 3.49 | Borough |
| Middlesex | 33 | 14,373 | 14,593 | -0.31% | 4,121 | 3.49 | Borough |
| Robertsville | 34 | 12,983 | 11,866 | 0.87% | 2,199 | 5.90 | CDP |
| Fords | 35 | 12,032 | 12,509 | -1.72% | 6,370 | 1.89 | CDP |
| Monmouth Junction | 36 | 11,466 | 8,911 | 5.25% | 2,617 | 4.38 | CDP |
| Kendall Park | 37 | 10,945 | 9,852 | 0.99% | 2,896 | 3.78 | CDP |
| South Amboy | 38 | 10,810 | 9,377 | 2.73% | 7,029 | 1.54 | City |
| South Amboy city | 39 | 10,237 | 9,377 | 0% | 6,656 | 1.54 | City |
| Dunellen borough | 40 | 9,422 | 7,617 | 7.08% | 8,872 | 1.06 | Borough |
| Dayton | 41 | 8,685 | 8,158 | 1.26% | 3,608 | 2.41 | CDP |
| Madison Park | 42 | 8,578 | 8,079 | 1.13% | 4,718 | 1.82 | CDP |
| Dunellen | 43 | 8,548 | 7,617 | 2.22% | 8,049 | 1.06 | Borough |
| Rutgers University-Busch Campus | 44 | 8,329 | 7,718 | 7.14% | 6,810 | 1.22 | CDP |
| Spotswood borough | 45 | 8,092 | 8,125 | 0.09% | 3,498 | 2.31 | Borough |
| Spotswood | 46 | 8,046 | 8,125 | -0.2% | 3,479 | 2.31 | Borough |
| Yorketown | 47 | 7,374 | 6,739 | 0.77% | 3,088 | 2.39 | CDP |
| Milltown borough | 48 | 6,980 | 7,018 | 0.09% | 4,492 | 1.55 | Borough |
| Milltown | 49 | 6,934 | 7,018 | -0.24% | 4,462 | 1.55 | Borough |
| Strathmore | 50 | 6,816 | 7,514 | -0.42% | 3,462 | 1.97 | CDP |
| Laurence Harbor | 51 | 6,389 | 6,041 | -0.14% | 2,166 | 2.95 | CDP |
| Jamesburg borough | 52 | 5,751 | 5,763 | 0.14% | 6,520 | 0.88 | Borough |
| Jamesburg | 53 | 5,716 | 5,763 | -0.16% | 6,481 | 0.88 | Borough |
| Port Reading | 54 | 4,118 | 3,973 | 0.64% | 2,084 | 1.98 | CDP |
| Cranbury township | 55 | 3,964 | 3,899 | 0.05% | 298 | 13.28 | Township |
| Menlo Park Terrace | 56 | 3,896 | 2,503 | 7.15% | 10,473 | 0.37 | CDP |
| Hopelawn | 57 | 3,638 | 2,457 | 7.16% | 8,325 | 0.44 | CDP |
| Keasbey | 58 | 3,431 | 2,825 | 7.15% | 2,350 | 1.46 | CDP |
| Clearbrook | 59 | 3,255 | 2,648 | 7.14% | 4,300 | 0.76 | CDP |
| Rutgers University-Livingston Campus | 60 | 3,214 | 1,941 | 7.13% | 2,406 | 1.34 | CDP |
| Monroe Manor | 61 | 3,186 | 2,180 | 7.13% | 11,179 | 0.28 | CDP |
| Cliffwood Beach | 62 | 2,962 | 3,024 | -0.5% | 3,269 | 0.91 | CDP |
| Forsgate | 63 | 2,875 | 1,803 | 7.16% | 3,286 | 0.88 | CDP |
| Rossmoor | 64 | 2,799 | 2,700 | 0.32% | 4,147 | 0.68 | CDP |
| Plainsboro Center | 65 | 2,780 | 2,715 | 0.18% | 3,782 | 0.73 | CDP |
| Sewaren | 66 | 2,680 | 2,708 | -0.19% | 2,193 | 1.22 | CDP |
| Regency Monroe | 67 | 2,675 | 1,891 | 7.13% | 3,690 | 0.72 | CDP |
| Concordia | 68 | 2,614 | 2,520 | -1.21% | 3,395 | 0.77 | CDP |
| Cranbury | 69 | 2,492 | 2,213 | 0.81% | 2,036 | 1.22 | CDP |
| Helmetta borough | 70 | 2,441 | 2,454 | 0.08% | 2,948 | 0.83 | Borough |
| Helmetta | 71 | 2,425 | 2,454 | -0.25% | 2,929 | 0.83 | Borough |
| Whittingham | 72 | 2,410 | 2,507 | -0.17% | 3,513 | 0.69 | CDP |
| Stonebridge | 73 | 2,309 | 1,649 | 7.15% | 5,041 | 0.46 | CDP |
| Brownville | 74 | 2,133 | 2,412 | -0.79% | 1,993 | 1.07 | CDP |
| Deans | 75 | 1,311 | 1,351 | 7.11% | 1,169 | 1.12 | CDP |
| The Ponds | 76 | 1,146 | 911 | 7.1% | 5,257 | 0.22 | CDP |
| Renaissance Monroe | 77 | 864 | 556 | 7.2% | 4,937 | 0.17 | CDP |
| Encore Monroe | 78 | 688 | 560 | 7.17% | 3,583 | 0.19 | CDP |
Edison township is the largest city in Middlesex County, with a population of 106,512.
Encore Monroe is the smallest city in Middlesex County.
There are 78 cities in Middlesex County, New Jersey.