43 ZIP Codes
| Zip Code | City | Population ↓ |
|---|---|---|
| 22030 | Fairfax | 61,332 |
| 22003 | Annandale | 57,755 |
| 20171 | Herndon | 51,286 |
| 22015 | Burke | 44,647 |
| 20170 | Herndon | 43,866 |
| 20120 | Centreville | 42,896 |
| 22033 | Fairfax | 39,526 |
| 22031 | Fairfax | 37,276 |
| 22042 | Falls Church | 35,483 |
| 22079 | Lorton | 35,284 |
| 22309 | Alexandria | 34,316 |
| 22153 | Springfield | 32,664 |
| 20191 | Reston | 31,011 |
| 22101 | McLean | 30,953 |
| 22306 | Alexandria | 30,602 |
| 22315 | Alexandria | 30,404 |
| 22032 | Fairfax | 29,240 |
| 22102 | McLean | 29,184 |
| 22041 | Falls Church | 29,183 |
| 22152 | Springfield | 28,814 |
| 22310 | Alexandria | 28,136 |
| 22150 | Springfield | 27,955 |
| 20121 | Centreville | 27,788 |
| 22182 | Vienna | 27,783 |
| 22312 | Alexandria | 26,768 |
| 22180 | Vienna | 26,568 |
| 22043 | Falls Church | 25,750 |
| 20151 | Chantilly | 22,610 |
| 20190 | Reston | 22,012 |
| 22039 | Fairfax Station | 19,626 |
| 22124 | Oakton | 18,091 |
| 22066 | Great Falls | 17,185 |
| 22151 | Springfield | 17,017 |
| 22303 | Alexandria | 16,922 |
| 22181 | Vienna | 15,760 |
| 20124 | Clifton | 14,375 |
| 22308 | Alexandria | 14,090 |
| 22044 | Falls Church | 13,996 |
| 20194 | Reston | 12,275 |
| 22060 | Fort Belvoir | 10,641 |
| 22307 | Alexandria | 10,343 |
| 22027 | Dunn Loring | 1,939 |
| 22035 | Fairfax | 0 |
The data shown reflect ZCTAs from the US Census. As of 2025, there are 43 ZCTAs in Fairfax County, Virginia (US Census).