Clayton, OH -- U.S. city in Ohio Population (2000): 13347 Housing Units (2000): 5193 Land area (2000): 18.443601 sq. miles (47.768704 sq. km) Water area (2000): 0.112628 sq. miles (0.291704 sq. km) Total area (2000): 18.556229 sq. miles (48.060408 sq. km) FIPS code: 15644 Located within: Ohio (OH), FIPS 39 Location: 39.851461 N, 84.311212 W ZIP Codes (1990): 45315 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Clayton, OH Clayton