| County : | Johnson County |
| State : | Illinois (IL) |
| Land Area : | 343.91 sq mi |
| Water Area : | 4.95 sq mi |
| Latitude : | 37.4608153 |
| Longitude : | -88.8829622 |
| Population (2010): | 12,582 |
| Population Estimate (2012) : | 12,653 |
| Population Density : | 36.58/sq mi |
| Housing Units (2012) : | 5,598 |
| Median Household Income (2012) : | $42,027 (Illinois : $56,853, USA : $53,046) |
| Median Family Income (2012) : | $52,370 (Illinois : $70,144, USA : $64,585) |
| Median House Price (2012) : | $92,500 (Illinois : $190,800, USA : $181,400) |
Johnson County Cities / Towns
| Belknap Village (104) | Buncombe Village (203) | Cypress Village (234) |
| Goreville Village (1,049) | Marion City (17,193) | New Burnside Village (211) |
| Simpson Village (60) | Vienna City (1,434) |
Johnson County Zip Codes
| 62908 (467) | 62912 (1,179) | 62922 (3,119) |
| 62923 (518) | 62939 (3,119) | 62943 (715) |
| 62967 (326) | 62972 (1,205) | 62985 (845) |
| 62995 (5,284) |