The Diversity Index is a scale of 0 to 100 that represents the likelyhood that two persons, chosen at random from the same area, belong to different race or ethnic groups. If an area's entire population belongs to one race AND one ethnic group, then the area has zero diversity. An area's diversity index increases to 100 when the population is evenly divided into two or more race/ethnic groups.
| Name | County | Diversity Index | |
|---|---|---|---|
| 1. | City of Park City | Lake | 88.6 |
| 2. | City of Waukegan | Lake | 88.0 |
| 3. | City of Blue Island | Cook | 87.6 |
| 4. | Village of Dixmoor | Cook | 85.1 |
| 5. | Village of Fairmont City | St. Clair | 84.6 |
| 6. | City of Chicago Heights | Cook | 84.6 |
| 7. | Village of Posen | Cook | 83.8 |
| 8. | Village of Stone Park | Cook | 83.6 |
| 9. | City of North Chicago | Lake | 83.3 |
| 10. | City of Chicago | Cook | 83.1 |
| 11. | Village of Hillside | Cook | 82.9 |
| 12. | Village of Glendale Heights | DuPage | 82.8 |
| 13. | Village of Berkeley | Cook | 82.8 |
| 14. | City of Aurora | Kane | 82.8 |
| 15. | City of Zion | Lake | 82.4 |
| 16. | Village of Bolingbrook | Will | 81.9 |
| 17. | Village of Hanover Park | DuPage | 81.5 |
| 18. | Village of McCook | Cook | 81.4 |
| 19. | Village of Summit | Cook | 81.4 |
| 20. | City of Berwyn | Cook | 81.3 |
