Hillsboro, IL -- U.S. city in Illinois Population (2000): 4359 Housing Units (2000): 1944 Land area (2000): 3.587983 sq. miles (9.292833 sq. km) Water area (2000): 1.741824 sq. miles (4.511304 sq. km) Total area (2000): 5.329807 sq. miles (13.804137 sq. km) FIPS code: 35047 Located within: Illinois (IL), FIPS 17 Location: 39.164973 N, 89.484572 W ZIP Codes (1990): 62049 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Hillsboro, IL Hillsboro