Round Rock, TX ZIP Codes
Round Rock, Texas has 6 ZIP codes: 3 for street addresses (, and ), 2 for PO boxes ( and ) and 1 for a single organization.
Your street decides which one you use.
Which Round Rock ZIP code is my address in?
Street ranges from the Census Bureau, 2026. PO box and organization ZIP codes are not found by street. A new street may be missing: address not found?
Round Rock ZIP code map
Tap or point to an area to see its ZIP code.Full-size map
78680, 78682 and 78683 have no area on the map: they are PO box or single-organization ZIP codes. Dashed line: Round Rock city limits.
Map: Census Bureau ZIP Code Tabulation Areas (2020) and place limits (2024).
All Round Rock ZIP codes by type
| ZIP | Type and post office or station |
|---|---|
| 78664 | street delivery Round Rock |
| 78665 | street delivery Round Rock |
| 78680 | PO boxes at the Round Rock West post office Round Rock West |
| 78681 | street delivery Round Rock West |
| 78682 | one organization Round Rock |
| 78683 | PO boxes at the Round Rock post office Round Rock |
Why your mail may say Round Rock when you live outside it
Round Rock ZIP codes also cover Brushy Creek, so a letter addressed to Round Rock can go to a home outside the city limits.
A ZIP code does not set your city, school district or tax. Williamson County property records show which city you are in.
Round Rock ZIP code questions
What is the main ZIP code for Round Rock?
78664, the ZIP code of the main Round Rock post office at 2250 Double Creek Dr.
Which Round Rock ZIP codes are for PO boxes only?
78680 and 78683. Mail to them goes to boxes at the post office, not to street addresses.
What county is Round Rock in?
Williamson County, with parts in Travis County.
ZIP codes for towns near Round Rock
More towns near Round Rock: Harker Heights, Killeen, Kyle, Temple, Copperas Cove, San Marcos, Canyon Lake, New Braunfels, Seguin.
Sources and last checked
USPS ZIP Locale Detail (October 1, 2026), GeoNames (CC BY 4.0), U.S. Census Bureau, HUD-USPS crosswalk.
Checked October 20, 2026. Sources · How we build our lists · Corrections