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 |
|---|---|---|---|---|---|---|---|
| Bel Air South | 1 | 58,676 | 55,024 | 1.35% | 2,758 | 21.3 | CDP |
| Bel Air North | 2 | 31,431 | 30,639 | 0.19% | 1,968 | 16.0 | CDP |
| Edgewood | 3 | 25,042 | 25,065 | -0.15% | 1,464 | 17.1 | CDP |
| Aberdeen | 4 | 18,586 | 16,265 | 3.22% | 2,670 | 7.0 | City |
| Havre Grace | 5 | 15,098 | 14,834 | 0.44% | 2,543 | 5.9 | City |
| Bel Air | 6 | 10,421 | 10,697 | -0.66% | 3,438 | 3.0 | Town |
| Fallston | 7 | 10,118 | 9,118 | 0.83% | 723 | 14.0 | CDP |
| Abingdon | 8 | 5,963 | 5,324 | 7.69% | 2,159 | 2.8 | CDP |
| Riverside | 9 | 5,840 | 5,888 | -0.71% | 2,235 | 2.6 | CDP |
| Pleasant Hills | 10 | 4,016 | 4,017 | 1.16% | 921 | 4.4 | CDP |
| Aberdeen Proving Ground | 11 | 2,805 | 2,724 | 1.85% | 252 | 11.1 | CDP |
| Jarrettsville | 12 | 2,637 | 2,827 | -0.75% | 305 | 8.6 | CDP |
| Perryman | 13 | 2,413 | 2,397 | 0.21% | 443 | 5.4 | CDP |
| Bel Air | 14 | 1,739 | 1,504 | 2.05% | 2,531 | 0.7 | CDP |
| Pylesville | 15 | 794 | 1,015 | 0.89% | 167 | 4.7 | CDP |
| Darlington | 16 | 490 | 522 | 1.24% | 469 | 1.0 | CDP |
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.
Bel Air South is the largest city in Harford County.
Darlington is the smallest city in Harford County.
There are 16 cities in Harford County, Maryland.