ZIP codes in Loudoun County
40 ZIPs touch Loudoun County, Virginia. The blue dashed line is the county border; orange ZIPs reach into it.
40
ZIP codes
6
cross the county line
495,114
people in these ZIPs
133
counties in VA
Most people
Loudoun County ZIP list
More counties in Virginia
- King George County6
- King William County6
- King and Queen County16
- Lancaster County10
- Lee County11
- Lexington city1
- Louisa County13
- Lunenburg County12
- Lynchburg city7
- Madison County23
- Manassas Park city1
- Manassas city3
Questions people actually ask
How many ZIP codes are in Loudoun County, Virginia?
40 ZIP codes reach into Loudoun County, including 19 PO Box or single-address ZIPs placed by the town they serve. 6 of them are only partly in the county and also cover a neighboring county.
Which ZIP code in Loudoun County has the most people?
20147 (Ashburn) has about 67,692 residents, the most of any ZIP touching Loudoun County, in the Census Bureau’s ACS 2020–2024 estimates.
Can a ZIP code be in Loudoun County and another county?
Yes. ZIP codes follow mail routes, not county lines. Rows marked with a percentage show how much of that ZIP’s land is in Loudoun County. For one address, pin the exact spot on the ZIP finder to see its county.
Where does this list come from?
ZIP areas and their county overlaps come from the Census Bureau’s 2020 ZIP Code Tabulation Area to county relationship file. PO Box ZIPs have no area, so each is placed in the county of the ZIP area nearest the town it serves.
Keep exploring
Updated 2026-11-10 · Where the data comes from