Round Rock Is the Largest City in Williamson County

Williamson County is home to several cities that have grown rapidly since the 1970s. Round Rock, in the southern part of the county, has a population of over 110,000 and is the county's most populous city. Georgetown, the county seat, has over 56,000 residents. Cedar Park and Leander also have large and growing populations.

This growth is driven largely by Austin's expansion northward. Each city has its own government, codes, and utility systems. If you are moving to the county, confirm which city (if any) your property falls in, since rules and taxes vary.