| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Gaithersburg | 1 | 71,642 | 69,428 | 0.74% | 6,941 | 10 | City |
| Rockville | 2 | 67,431 | 67,270 | -0.2% | 4,970 | 14 | City |
| Takoma Park | 3 | 17,206 | 17,579 | -0.31% | 8,233 | 2 | City |
| Poolesville | 4 | 5,990 | 5,782 | 0.81% | 1,583 | 4 | Town |
| Kensington | 5 | 2,792 | 2,110 | 5.28% | 5,551 | 1 | Town |
| Chevy Chase | 6 | 2,788 | 2,891 | -0.57% | 5,996 | 0 | Town |
| Chevy Chase Village | 7 | 1,967 | 2,037 | -0.56% | 4,683 | 0 | Town |
| Somerset | 8 | 1,144 | 1,190 | -0.61% | 4,145 | 0 | Town |
| Garrett Park | 9 | 954 | 985 | -0.52% | 3,801 | 0 | Town |
| Chevy Chase View | 10 | 947 | 978 | -0.53% | 3,534 | 0 | Town |
| Martin's Additions | 11 | 870 | 920 | -1.02% | 6,304 | 0 | Village |
| Chevy Chase Section Three | 12 | 770 | 792 | -0.39% | 6,581 | 0 | Village |
| North Chevy Chase | 13 | 660 | 684 | -0.6% | 5,690 | 0 | Village |
| Chevy Chase Section Five | 14 | 654 | 671 | -0.46% | 6,112 | 0 | Village |
| Laytonsville | 15 | 617 | 586 | 0.98% | 589 | 1 | Town |
| Washington Grove | 16 | 493 | 503 | -0.4% | 1,467 | 0 | Town |
| Glen Echo | 17 | 277 | 280 | 0% | 2,689 | 0 | Town |
| Brookeville | 18 | 155 | 163 | -1.27% | 1,107 | 0 | Town |
| Barnesville | 19 | 143 | 143 | 0% | 292 | 0 | Town |
Gaithersburg is the largest city in Montgomery County, with a population of 71,642.
Barnesville is the smallest city in Montgomery County, with a population of 143.
There are 19 cities in Montgomery County, Maryland.