37 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Leesburg | 1 | 50,178 | 48,307 | 0.7% | 3,987 | 13 | Town |
| Leesburg | 2 | 50,178 | 48,443 | 0.7% | 3,987 | 13 | Town |
| Ashburn | 3 | 45,971 | 44,090 | 0.36% | 3,006 | 15 | CDP |
| South Riding | 4 | 35,634 | 32,526 | 2.18% | 5,206 | 7 | CDP |
| Sterling | 5 | 31,867 | 30,872 | 0.85% | 5,843 | 5 | CDP |
| Brambleton | 6 | 26,034 | 20,843 | 4.33% | 4,524 | 6 | CDP |
| Stone Ridge | 7 | 18,258 | 15,034 | 4.2% | 7,063 | 3 | CDP |
| Broadlands | 8 | 15,149 | 14,146 | 1.26% | 4,686 | 3 | CDP |
| Lansdowne | 9 | 13,237 | 12,679 | 1.01% | 3,274 | 4 | CDP |
| Sugarland Run | 10 | 13,073 | 12,656 | 0.65% | 6,507 | 2 | CDP |
| Cascades | 11 | 12,700 | 12,132 | 0.42% | 3,445 | 4 | CDP |
| Loudoun Valley Estates | 12 | 12,228 | 9,673 | 4.9% | 4,359 | 3 | CDP |
| Lowes Island | 13 | 11,392 | 11,319 | 0.37% | 3,776 | 3 | CDP |
| Belmont | 14 | 10,869 | 9,341 | 3.1% | 4,024 | 3 | CDP |
| Countryside | 15 | 9,540 | 9,517 | -0.37% | 3,716 | 3 | CDP |
| Purcellville | 16 | 8,969 | 8,931 | 0.04% | 2,650 | 3 | Town |
| Purcellville | 17 | 8,969 | 8,946 | 0.04% | 2,650 | 3 | Town |
| Moorefield | 18 | 6,864 | 4,099 | 7.15% | 6,042 | 1 | CDP |
| Dulles Town Center | 19 | 6,205 | 5,362 | 1.75% | 2,583 | 2 | CDP |
| University Center | 20 | 4,382 | 3,878 | 1.22% | 4,773 | 1 | CDP |
| One Loudoun | 21 | 3,474 | 2,151 | 7.16% | 5,479 | 1 | CDP |
| Arcola | 22 | 2,988 | 1,761 | 6.56% | 1,308 | 2 | CDP |
| Goose Creek Village | 23 | 2,915 | 2,193 | 7.13% | 7,712 | 0 | CDP |
| Oak Grove | 24 | 2,722 | 2,863 | 2.37% | 2,328 | 1 | CDP |
| Lovettsville | 25 | 2,721 | 2,696 | 0.07% | 3,050 | 1 | Town |
| Lovettsville | 26 | 2,721 | 2,709 | 0.07% | 3,050 | 1 | Town |
| Middleburg | 27 | 701 | 673 | 0.72% | 676 | 1 | Town |
| Middleburg | 28 | 701 | 673 | 0.72% | 676 | 1 | Town |
| Round Hill | 29 | 685 | 693 | -0.29% | 1,866 | 0 | Town |
| Round Hill | 30 | 685 | 692 | -0.29% | 1,866 | 0 | Town |
| Hamilton | 31 | 604 | 617 | -0.49% | 2,721 | 0 | Town |
| Hamilton | 32 | 604 | 617 | -0.49% | 2,721 | 0 | Town |
| Kincora | 33 | 396 | 13 | 7.03% | 739 | 1 | CDP |
| Waterford | 34 | 310 | 256 | 7.27% | 856 | 0 | CDP |
| Aldie | 35 | 264 | 233 | 7.32% | 1,091 | 0 | CDP |
| Hillsboro | 36 | 109 | 113 | -0.91% | 411 | 0 | Town |
| Hillsboro | 37 | 109 | 113 | -0.91% | 411 | 0 | Town |
Leesburg is the largest city in Loudoun County, with a population of 50,178.
Hillsboro is the smallest city in Loudoun County, with a population of 109.
There are 37 cities in Loudoun County, Virginia.