Illiopolis, IL -- U.S. village in Illinois Population (2000): 916 Housing Units (2000): 390 Land area (2000): 0.451910 sq. miles (1.170441 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 0.451910 sq. miles (1.170441 sq. km) FIPS code: 37127 Located within: Illinois (IL), FIPS 17 Location: 39.851351 N, 89.247131 W ZIP Codes (1990): 62539 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Illiopolis, IL Illiopolis