Updated November 2026
It’s one of the questions we hear most often, from buyers, from friends who just moved here, and lately even from AI search tools: is Ashburn a town? What about Sterling? And why does my friend in Lansdowne have a Leesburg address?
The short answer is no, Ashburn is not a town (or a city). It’s an unincorporated community, and so is Sterling. That sounds technical, but it actually tells you a lot about how Loudoun County works, so let’s dig in.
Loudoun’s Seven Incorporated Towns
According to Loudoun County, there are seven incorporated towns in Loudoun:
Incorporated towns have their own local government, with a mayor and town council, on top of the county. Living inside town limits can mean town services and town taxes in addition to county ones, so it’s worth asking about when you’re looking at a home.
So What Are Ashburn and Sterling?
Places like Ashburn, Sterling, Aldie, Bluemont, and Waterford are unincorporated communities. They don’t have their own town government, so Loudoun County handles everything directly. (No mayor of Ashburn, sorry to disappoint.)
The Census Bureau also draws its own boundaries, called “census-designated places,” just for counting people. That’s why you’ll sometimes see wildly different population numbers for the same community. In the 2020 Census, the Ashburn census-designated place had 46,349 residents. Ashburn’s two ZIP codes, 20147 and 20148, were home to 128,187 people. The difference is that the Census counts places like Brambleton, Broadlands, and One Loudoun as their own separate places, even though they all have Ashburn mailing addresses.
ZIP Codes: Where It Gets Interesting
For most people, “where you live” really comes down to your mailing address. Here’s how Loudoun County’s own ZIP code map lines up:
- Ashburn: 20147, 20148
- Leesburg: 20175, 20176
- Sterling: 20164, 20165, 20166
- Purcellville: 20132
- Round Hill: 20141
- Hamilton: 20158
- Lovettsville: 20180
- Waterford: 20197
- Middleburg: 20117
- Aldie: 20105
- Bluemont: 20135
- Chantilly: 20151, 20152
A Few Local Quirks
This is where Loudoun keeps things interesting.
- Lansdowne is Leesburg. It sits right between Leesburg and Ashburn, but its mailing address is Leesburg 20176.
- Hillsboro shares Purcellville’s ZIP code. Hillsboro is one of Loudoun’s seven incorporated towns, but the county’s ZIP map doesn’t give it a ZIP code of its own, so it uses Purcellville’s 20132.
- Potomac Falls is part of Sterling. It covers the area closer to the Potomac River, including Cascades, within Sterling’s 20165.
- South Riding has a Chantilly address. It’s in Loudoun County, but it uses Chantilly’s 20152 ZIP code.
- Bluemont crosses county and state lines. The 20135 ZIP code covers parts of Loudoun County and Clarke County, plus a small slice of Jefferson County, West Virginia. Two homes with a Bluemont address can be in different counties, or even different states.
- Brambleton, Broadlands, and One Loudoun are all Ashburn. Each has its own name and personality, but they all share Ashburn mailing addresses.
Why It Matters When You’re Buying
A mailing address doesn’t always tell you which county you’re in, whether you’re inside town limits, or which schools serve the home. All of those can affect your taxes, your services, and your day-to-day life. School assignments in particular are set by attendance zone, not ZIP code, so always confirm a specific address with the LCPS attendance zone tool.
If you’re trying to make sense of a particular neighborhood, that’s exactly the kind of thing we love helping with. Comment below or reach out anytime!
Cheers,
Heather
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