Williamson County, Texas

19 ZIP codes · 1,115.85 sq mi of land · FIPS 48491

Population	672,688
State	Texas
FIPS code	48491
Time zone	Central
Land area	1,115.85 sq mi
Center (lat, long)	30.6491, -97.6051

Area codes in this area

254 512 737

These are the area codes that most often serve Williamson County (including overlays). The exact area code depends on the phone number — landlines, mobiles and overlays can differ even on the same street.

Cities and towns (largest first)

Austin · 979,539 Round Rock · 127,786 Georgetown · 85,999 Cedar Park · 78,301 Hutto · 35,483 Taylor · 17,136FlorenceGrangerJarrellSchwertnerThrallCouplandLiberty HillWeir

ZIP codes in Williamson County

76527 Florence 76530 Granger 76537 Jarrell 76573 Schwertner 76574 Taylor 76578 Thrall 78613 Cedar Park 78615 Coupland 78626 Georgetown 78628 Georgetown 78633 Georgetown 78634 Hutto 78642 Liberty Hill 78664 Round Rock 78665 Round Rock 78674 Weir 78681 Round Rock 78717 Austin 78729 Austin

Population: U.S. Census Bureau, ACS 5-year estimates, 2024.