Fairfield is a city in Freestone County, Texas, United States. The population was 2,951 at the 2010 census, down from 3,094 at the 2000 census. It is the county seat of Freestone County and was founded as such in 1851.
Fairfield is located in the center of Freestone County at 31°43′19″N 96°9′29″W (31.721940, −96.158011). Interstate 45 passes through the west side of the city, leading north 88 miles (142 km) to Dallas and south 152 miles (245 km) to Houston. Access is from Exits 197 and 198. U.S. Route 84 runs directly through the city, leading east 35 miles (56 km) to Palestine and west 63 miles (101 km) to Waco. Texas State Highway 75 (Fairway) crosses US 84 at the west end of downtown, and leads northwest 14 miles (23 km) to Streetman and south 9 miles (14 km) to Dew.
According to the United States Census Bureau, the city has a total area of 5.4 square miles (14.1 km2), of which 0.004 square miles (0.01 km2), or 0.07%, is water.
As of the census of 2000, there were 3,094 people, 1,235 households, and 791 families living in the city. The population density was 685.6 people per square mile (264.9/km2). There were 1,431 housing units at an average density of 317.1 per square mile (122.5/km2).