Illinois is a state in the United States, is located in the Midwestern region of the country. It is the fifth most populated state (12,88,135 estimated) and the 25th biggest by area in the country (149,998 km2 at the density of 89 per km2).
Springfield is the state capital and the sixth biggest city in Illinois. With a population of 2,718,782 and a population density of 4,610 persons per km2 on a total area of 587 km2, Chicago is the biggest city in Illinois and the third-largest in the United States. Cicero city has the greatest population density of 5,536 people per square kilometer in a 15-square-kilometer area.
| Rank | Name | Population | Area (km²) | Density (Inhabitants/km²) | County |
|---|---|---|---|---|---|
| 1 | Chicago | 2,718,782 | 589 | 4,610 | Cook |
| 2 | Aurora | 199,963 | 116 | 1,718 | Kane |
| 3 | Rockford | 150,251 | 164 | 915 | Winnbago |
| 4 | Joliet | 147,806 | 162 | 910 | Will |
| 5 | Naperville | 144,864 | 100 | 1,447 | DuPage |
| 6 | Springfield | 117,006 | 154 | 757 | Sangamon |
| 7 | Peoria | 116,513 | 124 | 937 | Peoria |
| 8 | Elgin | 110,145 | 96 | 1,140 | Kane |
| 9 | Waukegan | 88,826 | 61 | 1,448 | Lake |
| 10 | Cicero | 84,103 | 15 | 5,536 | Cook |
| 11 | Champaign | 83,424 | 58 | 1,426 | Champaign |
| 12 | Bloomington | 78,902 | 70 | 1,117 | McLean |
| 13 | Arlington Heights | 75,994 | 42 | 1,768 | Cook |
| 14 | Evanston | 75,570 | 20 | 3,750 | Cook |
| 15 | Schaumburg | 74,907 | 49 | 1,506 | Cook |
| 16 | Decatur | 74,710 | 109 | 683 | Macon |
| 17 | Bolingbrook | 73,936 | 62 | 1,184 | Will |
| 18 | Palatine | 69,350 | 35 | 1,966 | Cook |
| 19 | Skokie | 65,176 | 26 | 2,500 | Cook |
| 20 | Des Plaines | 58,918 | 36 | 1,592 | Cook |
| 21 | Orland Park | 58,590 | 56 | 1,032 | Cook |
| 22 | Tinley Park | 57,282 | 41 | 1,380 | Cook |
| 23 | Oak Lawn | 57,073 | 22 | 2,570 | Cook |
| 24 | Berwyn | 56,758 | 10 | 5,614 | Cook |
| 25 | Mount Prospect | 54,771 | 26 | 2,043 | Cook |
