29 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Aurora | 1 | 180,935 | 180,260 | 0.06% | 3,999 | 45 | City |
| Naperville | 2 | 154,969 | 149,434 | 0.6% | 3,936 | 39 | City |
| Wheaton | 3 | 53,662 | 53,899 | -0.07% | 4,741 | 11 | City |
| Downers Grove | 4 | 50,737 | 50,182 | 0.18% | 3,463 | 15 | Village |
| Elmhurst | 5 | 46,298 | 45,727 | 0.21% | 4,531 | 10 | City |
| Lombard | 6 | 44,527 | 44,416 | 0.04% | 4,383 | 10 | Village |
| Bartlett | 7 | 40,565 | 41,023 | -0.19% | 2,571 | 16 | Village |
| Carol Stream | 8 | 39,454 | 39,760 | -0.13% | 4,242 | 9 | Village |
| Addison | 9 | 35,776 | 35,631 | 0.07% | 3,640 | 10 | Village |
| Woodridge | 10 | 34,096 | 34,116 | -0.01% | 3,540 | 10 | Village |
| Glendale Heights | 11 | 32,749 | 33,100 | -0.18% | 6,071 | 5 | Village |
| Glen Ellyn | 12 | 28,837 | 28,941 | -0.06% | 4,184 | 7 | Village |
| West Chicago | 13 | 25,422 | 25,563 | -0.09% | 1,652 | 15 | City |
| Westmont | 14 | 24,256 | 24,412 | -0.11% | 4,837 | 5 | Village |
| Lisle | 15 | 23,490 | 23,664 | -0.12% | 3,406 | 7 | Village |
| Roselle | 16 | 22,845 | 22,923 | -0.06% | 4,131 | 6 | Village |
| Bloomingdale | 17 | 22,756 | 22,353 | 0.3% | 3,363 | 7 | Village |
| Darien | 18 | 22,023 | 21,998 | 0.02% | 3,571 | 6 | City |
| Villa Park | 19 | 21,927 | 22,206 | -0.21% | 4,644 | 5 | Village |
| Bensenville | 20 | 18,557 | 18,772 | -0.19% | 3,354 | 6 | Village |
| Hinsdale | 21 | 17,713 | 17,368 | 0.33% | 3,831 | 5 | Village |
| Warrenville | 22 | 16,055 | 13,631 | 2.58% | 2,939 | 5 | City |
| Wood Dale | 23 | 13,957 | 14,034 | -0.09% | 2,914 | 5 | City |
| Winfield | 24 | 10,393 | 9,810 | 0.94% | 3,358 | 3 | Village |
| Itasca | 25 | 9,488 | 9,541 | -0.09% | 1,889 | 5 | Village |
| Willowbrook | 26 | 9,158 | 9,221 | -0.11% | 3,557 | 3 | Village |
| Clarendon Hills | 27 | 8,710 | 8,689 | 0.05% | 4,812 | 2 | Village |
| Oak Brook | 28 | 8,208 | 8,148 | 0.12% | 1,029 | 8 | Village |
| Wayne | 29 | 2,287 | 2,280 | 0.04% | 399 | 6 | Village |
Aurora is the largest city in DuPage County, with a population of 180,935.
Wayne is the smallest city in DuPage County, with a population of 2,287.
There are 29 cities in DuPage County, Illinois.