Sonterra is a planned community and census-designated place in Williamson County, Texas, United States. the population was 7,679 at the 2020 census. It was first listed as a CDP prior to the 2020 census. It is in the northern part of the county, bordered to the north by the city of Jarrell. Interstate 35 forms part of the western border of the community, with access from Exit 275. I-35 leads north 27 miles to Temple and south 40 miles to Austin, the state capital.