Mills County is a county located in Central Texas, United States. It was created on March 15, 1887, from parts of four existing counties—Brown, Comanche, Hamilton, and Lampasas—and named after John T. Mills. The 2020 census reported a population of 4,456. The county seat is Goldthwaite. A long-time resident of the county quipped that residing here is the closest a person could get to living in Mayberry.