16 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Bel Air South | 1 | 59,459 | 55,024 | 1.33% | 2,795 | 21.27 | CDP |
| Bel Air North | 2 | 31,493 | 30,639 | 0.2% | 1,972 | 15.97 | CDP |
| Edgewood | 3 | 25,004 | 25,065 | -0.15% | 1,462 | 17.10 | CDP |
| Aberdeen | 4 | 19,166 | 16,265 | 3.12% | 2,753 | 6.96 | City |
| Havre Grace | 5 | 15,164 | 14,834 | 0.44% | 2,554 | 5.94 | City |
| Bel Air | 6 | 10,352 | 10,697 | -0.66% | 3,415 | 3.03 | Town |
| Fallston | 7 | 10,201 | 9,118 | 0.82% | 729 | 14 | CDP |
| Abingdon | 8 | 6,389 | 5,324 | 7.14% | 2,313 | 2.76 | CDP |
| Riverside | 9 | 5,799 | 5,888 | -0.7% | 2,219 | 2.61 | CDP |
| Pleasant Hills | 10 | 4,062 | 4,017 | 1.15% | 932 | 4.36 | CDP |
| Aberdeen Proving Ground | 11 | 2,856 | 2,724 | 1.82% | 257 | 11.13 | CDP |
| Jarrettsville | 12 | 2,617 | 2,827 | -0.76% | 303 | 8.63 | CDP |
| Perryman | 13 | 2,418 | 2,397 | 0.21% | 444 | 5.45 | CDP |
| Bel Air | 14 | 1,773 | 1,504 | 1.96% | 2,581 | 0.69 | CDP |
| Pylesville | 15 | 802 | 1,015 | 1.01% | 169 | 4.74 | CDP |
| Darlington | 16 | 495 | 522 | 1.02% | 474 | 1.04 | CDP |
Bel Air South is the largest city in Harford County, with a population of 59,459.
Darlington is the smallest city in Harford County.
There are 16 cities in Harford County, Maryland.