Williamson County, Texas
Updated · Data: U.S. Census Bureau
Williamson County, Texas has its county seat in Georgetown and FIPS code 48491. About 643,889 people live here, the 12th most populated of the 254 Texas counties.
| County seat | Georgetown |
|---|---|
| FIPS code | 48491 (Texas 48 + county 491) · all Texas FIPS codes |
| Population | 643,889 (12th of 254) |
| Land area | 1,115.8 sq mi (47th largest; + 16.0 sq mi water) |
| People per sq mi | 577.1 |
| Time zone | Central time (America/Chicago) |
| Median home value | $414,600 |
| Median property tax paid | $7,079 a year (about 1.71% of the median home value: our calculation, not an official rate) |
| Official website | www.wilcotx.gov |
What counties border Williamson County?
Williamson County shares a border with 6 counties:
What cities and towns are in Williamson County?
16 places with 1,000+ people have residents here; together they hold about 76% of the county's population. The rest live in smaller communities and rural areas.
| Place | Population | Residents in this county |
|---|---|---|
| Austin | 967,862 | 6.5% (also in other counties) |
| Round Rock | 124,288 | 98.1% (also in other counties) |
| Georgetown | 78,803 | 100.0% |
| Cedar Park | 77,474 | 90.7% (also in other counties) |
| Leander | 67,880 | 85.3% (also in other counties) |
| Hutto | 32,188 | 100.0% |
| Brushy Creek (CDP) | 20,953 | 100.0% |
| Taylor | 16,767 | 100.0% |
| Sonterra (CDP) | 8,576 | 100.0% |
| Liberty Hill | 6,706 | 100.0% |
| Santa Rita Ranch (CDP) | 4,055 | 100.0% |
| Jarrell | 2,589 | 100.0% |
| Bartlett | 1,758 | 57.2% (also in other counties) |
| Serenada (CDP) | 1,513 | 100.0% |
| Florence | 1,215 | 100.0% |
| Granger | 1,015 | 100.0% |
CDP = census-designated place: a named community with no city government.
What ZIP codes are in Williamson County?
27 ZIP code areas with residents touch Williamson County; the ones marked * cross into another county.
- 76511*
- 76527*
- 76530
- 76537
- 76573
- 76574
- 76577*
- 76578*
- 78613*
- 78615*
- 78621*
- 78626
- 78628
- 78633
- 78634
- 78641*
- 78642*
- 78664*
- 78665
- 78674
- 78681
- 78717
- 78727*
- 78728*
- 78729*
- 78750*
- 78759*
Check an exact address with the address lookup, look up a ZIP code, or see how to confirm your county with official records.
Sources: Census TIGER/Line 2024 (boundary, area, neighbors); ACS 2019-2023 5-year (population, home value, taxes paid); Wikidata, CC0 (seat, website); timezone-boundary-builder (time zone). Data as of November 1, 2026. Not affiliated with any government agency.
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