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. | Town of Georgetown | Sussex | 86.5 |
| 2. | Town of Elsmere | New Castle | 75.8 |
| 3. | Bear Census Designated Place | New Castle | 75.1 |
| 4. | Wilmington Manor Census Designated Place | New Castle | 73.9 |
| 5. | Town of Newport | New Castle | 72.4 |
| 6. | Town of Frankford | Sussex | 71.0 |
| 7. | Town of Selbyville | Sussex | 68.9 |
| 8. | Town of Little Creek | Kent | 68.2 |
| 9. | Brookside Census Designated Place | New Castle | 68.2 |
| 10. | Dover Base Housing Census Designated Place | Kent | 68.1 |
| 11. | Town of Cheswold | Kent | 67.4 |
| 12. | Rodney Village Census Designated Place | Kent | 67.0 |
| 13. | City of Dover | Kent | 66.9 |
| 14. | City of Milford | Sussex | 66.6 |
| 15. | City of Wilmington | New Castle | 66.4 |
| 16. | Town of Bridgeville | Sussex | 66.4 |
| 17. | Glasgow Census Designated Place | New Castle | 64.4 |
| 18. | Town of Middletown | New Castle | 64.0 |
| 19. | City of Seaford | Sussex | 63.6 |
| 20. | Claymont Census Designated Place | New Castle | 63.1 |
