| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Granite City | 1 | 26,659 | 27,512 | -0.55% | 1,402 | 19 | City |
| Edwardsville | 2 | 26,384 | 26,819 | -0.3% | 1,320 | 20 | City |
| Alton | 3 | 24,865 | 25,640 | -0.59% | 1,587 | 16 | City |
| Collinsville | 4 | 23,578 | 24,363 | -0.59% | 1,527 | 15 | City |
| Godfrey | 5 | 17,577 | 17,805 | -0.24% | 511 | 34 | Village |
| Glen Carbon | 6 | 13,907 | 13,862 | 0.06% | 1,348 | 10 | Village |
| Troy | 7 | 11,986 | 11,433 | 0.78% | 1,921 | 6 | City |
| Wood River | 8 | 10,184 | 10,430 | -0.39% | 1,459 | 7 | City |
| Highland | 9 | 10,034 | 10,077 | -0.08% | 1,402 | 7 | City |
| Bethalto | 10 | 9,176 | 9,307 | -0.28% | 1,209 | 8 | Village |
| Maryville | 11 | 8,438 | 8,259 | 0.3% | 1,455 | 6 | Village |
| Pontoon Beach | 12 | 5,887 | 5,864 | 0% | 599 | 10 | Village |
| East Alton | 13 | 5,589 | 5,769 | -0.57% | 1,051 | 5 | Village |
| Madison | 14 | 3,045 | 3,146 | -0.59% | 215 | 14 | City |
| Washington Park | 15 | 2,435 | 2,573 | -1.06% | 954 | 3 | Village |
| Fairmont City | 16 | 2,132 | 2,257 | -1.02% | 344 | 6 | Village |
| South Roxana | 17 | 1,839 | 1,888 | -0.54% | 852 | 2 | Village |
| Venice | 18 | 1,441 | 1,490 | -0.62% | 779 | 2 | City |
| Roxana | 19 | 1,386 | 1,436 | -0.65% | 194 | 7 | Village |
| St. Jacob | 20 | 1,370 | 1,380 | -0.07% | 1,617 | 1 | Village |
| Hartford | 21 | 1,146 | 1,187 | -0.61% | 220 | 5 | Village |
| Worden | 22 | 1,060 | 1,093 | -0.56% | 1,487 | 1 | Village |
| Marine | 23 | 982 | 908 | 1.45% | 1,393 | 1 | Village |
| Hamel | 24 | 936 | 937 | -0.11% | 787 | 1 | Village |
| Livingston | 25 | 744 | 764 | -0.53% | 715 | 1 | Village |
| Alhambra | 26 | 610 | 620 | -0.49% | 807 | 1 | Village |
| New Douglas | 27 | 337 | 346 | -0.59% | 322 | 1 | Village |
| Sauget | 28 | 128 | 134 | -0.78% | 28 | 5 | Village |
Granite City is the largest city in Madison County, with a population of 26,659.
Sauget is the smallest city in Madison County, with a population of 128.
There are 28 cities in Madison County, Illinois.