Hamilton is a city in and the county seat of Hamilton County, Texas, United States, located in the state's central region. Its population was 2,895 …Hamilton is a city in and the county seat of Hamilton County, Texas, United States, located in the state's central region. Its population was 2,895 at the 2020 census. Hamilton is located in central Hamilton County. U.S. Route 281 passes through the center of the city, leading north 21 miles to Hico and south 16 miles to Evant. Texas State Highway 36 crosses US 281 in the center of town and leads 32 miles southeast to Gatesville and 33 miles northwest to Comanche. Texas State Highway 22 leads northeast from Hamilton 33 miles to Meridian.