Fairfield, IA -- U.S. city in Iowa Population (2000): 9509 Housing Units (2000): 4463 Land area (2000): 5.737137 sq. miles (14.859116 sq. km) Water area (2000): 0.133759 sq. miles (0.346433 sq. km) Total area (2000): 5.870896 sq. miles (15.205549 sq. km) FIPS code: 26445 Located within: Iowa (IA), FIPS 19 Location: 41.007166 N, 91.965910 W ZIP Codes (1990): 52556 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Fairfield, IA Fairfield