Hill County is a county in the U.S. state of Texas. As of the 2020 census, its population was 35,874. Its county seat is Hillsboro. The county is named for George Washington Hill, secretary of war and secretary of the navy under the Republic of Texas. Hill County is part of Central Texas, though not included in the Texas Hill Country.

Hillsboro is a city in and the county seat of Hill County, Texas, United States. It is located between Dallas, Fort Worth and Waco, directly on Interstate 35 in North Central Texas. Hillsboro draws trade from throughout the county, and from Interstate 35 travelers between Dallas, Fort Worth, and Waco.