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 | 2024 Pop. | 2020 Pop. | Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Niagara Falls | 1 | 47,291 | 48,521 | -0.65% | 3,358 | 14.1 | City |
| North Tonawanda | 2 | 29,897 | 30,433 | -0.45% | 2,962 | 10.1 | City |
| Lockport | 3 | 20,359 | 20,504 | -0.49% | 454 | 44.8 | Town |
| Lockport | 4 | 20,306 | 20,825 | -0.64% | 2,417 | 8.4 | City |
| Wheatfield | 5 | 18,430 | 18,575 | -0.22% | 660 | 27.9 | Town |
| Lewiston | 6 | 15,634 | 15,917 | -0.36% | 421 | 37.1 | Town |
| Newfane | 7 | 9,148 | 9,259 | -0.51% | 177 | 51.8 | Town |
| Niagara | 8 | 7,667 | 7,881 | -0.73% | 808 | 9.5 | Town |
| Royalton | 9 | 7,420 | 7,508 | -0.34% | 106 | 70.0 | Town |
| Pendleton | 10 | 7,036 | 7,027 | 0.33% | 260 | 27.1 | Town |
| Porter | 11 | 6,397 | 6,500 | -0.54% | 194 | 33.1 | Town |
| Wilson | 12 | 5,714 | 5,834 | -0.68% | 116 | 49.4 | Town |
| Cambria | 13 | 5,704 | 5,738 | -0.18% | 144 | 39.7 | Town |
| Hartland | 14 | 3,784 | 3,866 | -0.66% | 72 | 52.4 | Town |
| Somerset | 15 | 2,538 | 2,595 | -0.66% | 68 | 37.1 | Town |
| Lewiston | 16 | 2,491 | 2,527 | -0.36% | 2,271 | 1.1 | Village |
| Barker | 17 | 2,444 | 2,503 | -0.45% | 59 | 41.4 | Town |
| Youngstown | 18 | 1,825 | 1,859 | -0.49% | 1,688 | 1.1 | Village |
| Middleport | 19 | 1,684 | 1,731 | -0.71% | 1,931 | 0.9 | Village |
| Wilson | 20 | 1,211 | 1,241 | -0.66% | 1,490 | 0.8 | Village |
| Barker | 21 | 566 | 584 | -0.88% | 1,348 | 0.4 | Village |
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.
Niagara Falls is the largest city in Niagara County.
Barker is the smallest city in Niagara County.
There are 21 cities in Niagara County, New York.