19 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Gaithersburg | 1 | 70,988 | 69,477 | 0.43% | 6,878 | 10 | City |
| Rockville | 2 | 68,687 | 67,337 | 0.39% | 5,063 | 14 | City |
| Takoma Park | 3 | 17,916 | 17,613 | 0.34% | 8,572 | 2 | City |
| Poolesville | 4 | 5,886 | 5,734 | 0.51% | 1,555 | 4 | Town |
| Chevy Chase | 5 | 2,935 | 2,895 | 0.27% | 6,312 | 0 | Town |
| Kensington | 6 | 2,161 | 2,128 | 0.28% | 4,296 | 1 | Town |
| Chevy Chase Village | 7 | 2,076 | 2,048 | 0.24% | 4,943 | 0 | Town |
| Somerset | 8 | 1,207 | 1,184 | 0.33% | 4,373 | 0 | Town |
| Chevy Chase View | 9 | 1,020 | 1,003 | 0.29% | 3,806 | 0 | Town |
| Garrett Park | 10 | 1,007 | 991 | 0.3% | 4,012 | 0 | Town |
| Martin's Additions | 11 | 952 | 940 | 0.21% | 6,899 | 0 | Village |
| Chevy Chase Section Three | 12 | 804 | 793 | 0.25% | 6,872 | 0 | Village |
| North Chevy Chase | 13 | 693 | 680 | 0.29% | 5,974 | 0 | Village |
| Chevy Chase Section Five | 14 | 686 | 676 | 0.29% | 6,411 | 0 | Village |
| Laytonsville | 15 | 588 | 577 | 0.34% | 562 | 1 | Town |
| Washington Grove | 16 | 514 | 504 | 0.39% | 1,530 | 0 | Town |
| Glen Echo | 17 | 286 | 281 | 0.35% | 2,777 | 0 | Town |
| Brookeville | 18 | 169 | 164 | 0.6% | 1,207 | 0 | Town |
| Barnesville | 19 | 145 | 144 | 0% | 297 | 0 | Town |
Gaithersburg is the largest city in Montgomery County, with a population of 70,988.
Barnesville is the smallest city in Montgomery County, with a population of 145.
There are 19 cities in Montgomery County, Maryland.