The seat of Hill County
, Hillsboro, established in 1853, is located 55 miles southwest of Dallas
along I-35W on both Aquilla Lake and Katy Lake.
The population of Hillsboro was 7,072 in 1990. In the 1990s Hillsboro had a public library, a municipal airport, and several historic sites, including the M-K-T Railroad Station and the Hill County Courthouse and Jail.
Annual events include the county fair in March, the Hill County Round-up and Rodeo, and the Pioneer Day Celebration and Parade.