Chillicothe, OH -- U.S. city in Ohio Population (2000): 21796 Housing Units (2000): 10303 Land area (2000): 9.544021 sq. miles (24.718899 sq. km) Water area (2000): 0.197684 sq. miles (0.511998 sq. km) Total area (2000): 9.741705 sq. miles (25.230897 sq. km) FIPS code: 14184 Located within: Ohio (OH), FIPS 39 Location: 39.336525 N, 82.983822 W ZIP Codes (1990): 45601 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Chillicothe, OH Chillicothe