12 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Frederick | 1 | 92,322 | 78,395 | 3.11% | 3,759 | 25 | City |
| Mount Airy | 2 | 9,980 | 9,647 | 0.67% | 2,421 | 4 | Town |
| Brunswick | 3 | 9,319 | 7,799 | 3.37% | 2,845 | 3 | City |
| Walkersville | 4 | 6,626 | 6,169 | 1.39% | 1,391 | 5 | Town |
| Thurmont | 5 | 6,335 | 6,200 | 0.43% | 2,039 | 3 | Town |
| Middletown | 6 | 5,081 | 4,949 | 0.51% | 2,399 | 2 | Town |
| Emmitsburg | 7 | 2,958 | 2,768 | 1.3% | 1,829 | 2 | Town |
| Myersville | 8 | 1,880 | 1,802 | 0.8% | 1,470 | 1 | Town |
| New Market | 9 | 1,629 | 1,526 | 1.24% | 920 | 2 | Town |
| Woodsboro | 10 | 1,119 | 1,091 | 0.45% | 1,583 | 1 | Town |
| Rosemont | 11 | 270 | 265 | 0.37% | 486 | 1 | Village |
| Burkittsville | 12 | 145 | 142 | 0% | 319 | 0 | Town |
Frederick is the largest city in Frederick County, with a population of 92,322.
Burkittsville is the smallest city in Frederick County, with a population of 145.
There are 12 cities in Frederick County, Maryland.