| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Aurora | 1 | 181,666 | 180,264 | 0.09% | 4,015 | 45 | City |
| Naperville | 2 | 153,905 | 149,384 | 0.52% | 3,909 | 39 | City |
| Wheaton | 3 | 53,932 | 53,893 | -0.25% | 4,765 | 11 | City |
| Downers Grove | 4 | 50,404 | 50,168 | 0.08% | 3,440 | 15 | Village |
| Elmhurst | 5 | 46,141 | 45,712 | 0.07% | 4,516 | 10 | City |
| Lombard | 6 | 44,374 | 44,422 | -0.06% | 4,368 | 10 | Village |
| Bartlett | 7 | 40,750 | 41,025 | -0.26% | 2,583 | 16 | Village |
| Carol Stream | 8 | 39,216 | 39,762 | -0.25% | 4,217 | 9 | Village |
| Addison | 9 | 35,742 | 35,631 | -0.04% | 3,637 | 10 | Village |
| Woodridge | 10 | 33,986 | 34,111 | -0.12% | 3,528 | 10 | Village |
| Glendale Heights | 11 | 32,558 | 33,098 | -0.3% | 6,036 | 5 | Village |
| Glen Ellyn | 12 | 28,701 | 28,956 | -0.17% | 4,164 | 7 | Village |
| West Chicago | 13 | 25,240 | 25,562 | -0.22% | 1,640 | 15 | City |
| Westmont | 14 | 24,101 | 24,405 | -0.22% | 4,806 | 5 | Village |
| Lisle | 15 | 23,379 | 23,662 | -0.23% | 3,390 | 7 | Village |
| Roselle | 16 | 22,722 | 22,923 | -0.15% | 4,109 | 6 | Village |
| Bloomingdale | 17 | 22,516 | 22,344 | 0.18% | 3,328 | 7 | Village |
| Darien | 18 | 22,011 | 21,999 | -0.1% | 3,569 | 6 | City |
| Villa Park | 19 | 21,819 | 22,200 | -0.32% | 4,621 | 5 | Village |
| Bensenville | 20 | 18,473 | 18,758 | -0.28% | 3,339 | 6 | Village |
| Hinsdale | 21 | 17,612 | 17,375 | 0.22% | 3,810 | 5 | Village |
| Warrenville | 22 | 15,587 | 13,703 | 2.47% | 2,854 | 5 | City |
| Wood Dale | 23 | 14,050 | 14,217 | -0.22% | 2,934 | 5 | City |
| Winfield | 24 | 10,230 | 9,822 | 0.83% | 3,305 | 3 | Village |
| Itasca | 25 | 9,471 | 9,566 | -0.18% | 1,886 | 5 | Village |
| Willowbrook | 26 | 9,105 | 9,212 | -0.23% | 3,536 | 3 | Village |
| Clarendon Hills | 27 | 8,675 | 8,692 | -0.07% | 4,793 | 2 | Village |
| Oak Brook | 28 | 8,109 | 8,072 | 0.01% | 1,017 | 8 | Village |
| Wayne | 29 | 2,278 | 2,276 | 0% | 398 | 6 | Village |
Aurora is the largest city in DuPage County, with a population of 181,666.
Wayne is the smallest city in DuPage County, with a population of 2,278.
There are 29 cities in DuPage County, Illinois.