There are 22 cities in Union County, New Jersey.
Note: As defined by the US Census Bureau, a city's official boundaries often extend miles beyond the city itself and may even cross county lines. As such, several thousand US cities officially exist in two or more counties (and therefore appear on multiple counties' lists of cities.)
City | Rank | State | 2024 Population | 2020 Census | Annual Change | Density (mi²) | Area (mi²) |
|---|---|---|---|---|---|---|---|
| Elizabeth | 1 | New Jersey | 131,915 | 136,651 | -0.89% | 10,708 | 12.32 |
| Plainfield | 2 | New Jersey | 54,682 | 54,344 | 0.16% | 9,176 | 5.96 |
| Linden | 3 | New Jersey | 43,169 | 43,535 | -0.21% | 4,039 | 10.69 |
| Westfield | 4 | New Jersey | 30,201 | 30,877 | -0.56% | 4,492 | 6.72 |
| Rahway | 5 | New Jersey | 29,720 | 29,666 | 0.05% | 7,628 | 3.90 |
| South Plainfield | 6 | New Jersey | 24,169 | 24,287 | -0.12% | 2,913 | 8.30 |
| North Plainfield | 7 | New Jersey | 22,527 | 22,747 | -0.24% | 8,025 | 2.81 |
| Roselle | 8 | New Jersey | 22,049 | 22,605 | -0.63% | 8,368 | 2.63 |
| Summit | 9 | New Jersey | 22,046 | 22,638 | -0.67% | 3,678 | 5.99 |
| Roselle Park | 10 | New Jersey | 13,634 | 14,004 | -0.67% | 11,130 | 1.23 |
| New Providence | 11 | New Jersey | 13,357 | 13,681 | -0.6% | 3,622 | 3.69 |
| Kenilworth | 12 | New Jersey | 8,163 | 8,391 | -0.69% | 3,802 | 2.15 |
| Fanwood | 13 | New Jersey | 7,564 | 7,746 | -0.59% | 5,645 | 1.34 |
| Dunellen | 14 | New Jersey | 7,535 | 7,615 | -0.27% | 7,095 | 1.06 |
| Mountainside | 15 | New Jersey | 6,912 | 7,002 | -0.32% | 1,730 | 4 |
| Garwood | 16 | New Jersey | 5,586 | 4,430 | 5.46% | 8,594 | 0.65 |
| Vauxhall | 17 | New Jersey | 5,243 | 5,677 | -0.83% | 8,902 | 0.59 |
| Union | 18 | New Jersey | 3,226 | 2,591 | 4.06% | 12,651 | 0.26 |
| Cranford | 19 | New Jersey | 1,496 | 2,008 | -7.2% | 4,439 | 0.34 |
| Kean University | 20 | New Jersey | 1,437 | 1,187 | 4.58% | 4,921 | 0.29 |
| Springfield | 21 | New Jersey | 1,425 | 1,498 | -1.25% | 3,673 | 0.39 |
| Connecticut Farms | 22 | New Jersey | 440 | 566 | -6.58% | 4,783 | 0.09 |
Note: City markers shown outside the county boundary mean that a part of the city extends into this county, but is primarily located in an adjacent county.
Elizabeth is the largest city in Union County.
Connecticut Farms is the smallest city in Union County.
There are 22 cities in Union County, New Jersey.