St. Johns -- U.S. County in Florida Population (2000): 123135 Housing Units (2000): 58008 Land area (2000): 609.009524 sq. miles (1577.327360 sq. km) Water area (2000): 212.417783 sq. miles (550.159510 sq. km) Total area (2000): 821.427307 sq. miles (2127.486870 sq. km) Located within: Florida (FL), FIPS 12 Location: 29.881862 N, 81.358139 W Headwords: St. Johns St. Johns, FL St. Johns County St. Johns County, FL