19 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Gaithersburg | 1 | 71,290 | 69,477 | 0.43% | 6,907 | 10 | City |
| Rockville | 2 | 68,957 | 67,337 | 0.39% | 5,083 | 14 | City |
| Takoma Park | 3 | 17,977 | 17,613 | 0.34% | 8,601 | 2 | City |
| Poolesville | 4 | 5,917 | 5,734 | 0.53% | 1,563 | 4 | Town |
| Chevy Chase | 5 | 2,943 | 2,895 | 0.27% | 6,329 | 0 | Town |
| Kensington | 6 | 2,168 | 2,128 | 0.32% | 4,310 | 1 | Town |
| Chevy Chase Village | 7 | 2,082 | 2,048 | 0.29% | 4,957 | 0 | Town |
| Somerset | 8 | 1,212 | 1,184 | 0.41% | 4,391 | 0 | Town |
| Chevy Chase View | 9 | 1,024 | 1,003 | 0.39% | 3,821 | 0 | Town |
| Garrett Park | 10 | 1,010 | 991 | 0.3% | 4,024 | 0 | Town |
| Martin's Additions | 11 | 955 | 940 | 0.32% | 6,920 | 0 | Village |
| Chevy Chase Section Three | 12 | 806 | 793 | 0.25% | 6,889 | 0 | Village |
| North Chevy Chase | 13 | 696 | 680 | 0.43% | 6,000 | 0 | Village |
| Chevy Chase Section Five | 14 | 688 | 676 | 0.29% | 6,430 | 0 | Village |
| Laytonsville | 15 | 590 | 577 | 0.34% | 564 | 1 | Town |
| Washington Grove | 16 | 516 | 504 | 0.39% | 1,536 | 0 | Town |
| Glen Echo | 17 | 287 | 281 | 0.35% | 2,786 | 0 | Town |
| Brookeville | 18 | 170 | 164 | 0.59% | 1,214 | 0 | Town |
| Barnesville | 19 | 145 | 144 | 0% | 297 | 0 | Town |
Gaithersburg is the largest city in Montgomery County, with a population of 71,290.
Barnesville is the smallest city in Montgomery County, with a population of 145.
There are 19 cities in Montgomery County, Maryland.