Illinois Counties Ranked by Area
Rank, county, total area (in square miles)
- McLean, 1174.05
- La Salle, 1137.41
- Iroquois, 1108.09
- Livingston, 1035.63
- Champaign, 987.74
- Cook, 949.20
- Vermilion, 891.67
- Fulton, 873.68
- Sangamon, 867.37
- Bureau, 865.96
- Adams, 861.86
- Macoupin, 857.93
- Will, 841.22
- Pike, 837.40
- Henry, 817.22
- Hancock, 805.69
- Shelby, 759.95
- Ogle, 757.12
- Madison, 732.09
- Lee, 722.21
- Fayette, 717.64
- Knox, 712.37
- Wayne, 707.76
- Christian, 707.56
- Montgomery, 701.92
- Whiteside, 691.50
- Kankakee, 674.62
- St Clair, 666.66
- Tazewell, 651.28
- Dekalb, 629.22
- Peoria, 623.69
- Edgar, 616.99
- Jo Daviess, 613.63
- Logan, 612.32
- McHenry, 606.12
- Jackson, 599.01
- Randolph, 588.68
- McDonough, 583.92
- Macon, 579.62
- Jefferson, 577.55
- Marion, 569.69
- Morgan, 566.72
- Mercer, 562.12
- Stephenson, 560.06
- Washington, 557.82
- Mason, 557.44
- Greene, 541.04
- Warren, 538.32
- Woodford, 537.33
- Kane, 519.67
- Winnebago, 515.20
- Coles, 504.87
- Clark, 499.36
- Clinton, 497.76
- White, 496.49
- Jasper, 492.90
- Ford, 481.40
- Effingham, 474.92
- Lake, 467.18
- Clay, 464.22
- Carroll, 462.70
- Rock Island, 447.32
- Perry, 442.30
- Crawford, 440.97
- Williamson, 439.51
- Schuyler, 436.62
- Piatt, 434.62
- Hamilton, 431.24
- Franklin, 427.09
- Grundy, 426.49
- Union, 417.84
- Douglas, 412.83
- Dewitt, 400.71
- Marshall, 395.01
- Monroe, 393.49
- Henderson, 391.97
- Saline, 382.94
- Cass, 379.55
- Bond, 378.66
- Jersey, 373.43
- Pope, 370.46
- Lawrence, 369.94
- Richland, 358.02
- Johnson, 345.03
- Cumberland, 342.94
- Moultrie, 340.35
- Dupage, 333.51
- Gallatin, 324.70
- Kendall, 319.42
- Menard, 311.94
- Brown, 303.95
- Stark, 285.67
- Calhoun, 280.66
- Boone, 279.87
- Alexander, 250.75
- Scott, 250.06
- Massac, 239.30
- Wabash, 225.04
- Edwards, 220.28
- Pulaski, 201.20
- Hardin, 179.48
- Putnam, 170.51
Updated 9/29/2009 JKH