As of the census of 2000, there were 3,094people, 1,235households, and 791families residing in the city. The population density was 685.6people per square mile (264.9Square kilometers). There were 1,431housing units at an average density of 317.1per square mile (122.5Square kilometers). Fairfield is a city in Freestone County, Texas, United States. The population was 3,094 at the 2000 census. It is the county seat of Freestone County. According to the United States Census Bureau, the city has a total area of 4.5square miles (12Square kilometers), all of it land. Also according to the 2010 United States Census Bureau, the population of Fairfield is 3,705.