37 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Hillsboro | 1 | 6,796 | 6,941 | -0.4% | 188 | 36 | Township |
| Litchfield | 2 | 6,544 | 6,758 | -0.65% | 731 | 9 | City |
| Hillsboro | 3 | 5,736 | 5,861 | -0.43% | 665 | 9 | City |
| North Litchfield | 4 | 4,790 | 4,942 | -0.58% | 132 | 36 | Township |
| South Litchfield | 5 | 3,192 | 3,283 | -0.5% | 86 | 37 | Township |
| Nokomis | 6 | 2,733 | 2,819 | -0.55% | 75 | 36 | Township |
| Nokomis | 7 | 2,113 | 2,182 | -0.66% | 1,673 | 1 | City |
| East Fork | 8 | 1,978 | 2,040 | -0.65% | 34 | 58 | Township |
| Raymond | 9 | 1,098 | 1,132 | -0.54% | 30 | 36 | Township |
| Witt | 10 | 996 | 1,028 | -0.6% | 27 | 37 | Township |
| Raymond | 11 | 913 | 943 | -0.65% | 726 | 1 | Village |
| Bois D'Arc | 12 | 901 | 928 | -0.44% | 17 | 55 | Township |
| Irving | 13 | 850 | 879 | -0.7% | 25 | 34 | Township |
| Butler | 14 | 842 | 880 | -0.47% | 12 | 72 | Township |
| Witt | 15 | 761 | 786 | -0.65% | 615 | 1 | City |
| Taylor Springs | 16 | 722 | 737 | -0.41% | 684 | 1 | Village |
| Butler Grove | 17 | 710 | 727 | -0.28% | 20 | 36 | Township |
| Farmersville | 18 | 662 | 684 | -0.75% | 936 | 1 | Village |
| Coffeen | 19 | 624 | 642 | -0.64% | 537 | 1 | City |
| Grisham | 20 | 612 | 626 | -0.49% | 25 | 24 | Township |
| Schram City | 21 | 550 | 568 | -0.72% | 972 | 1 | Village |
| Audubon | 22 | 492 | 506 | -0.61% | 9 | 54 | Township |
| Zanesville | 23 | 411 | 424 | -0.48% | 11 | 37 | Township |
| Pitman | 24 | 395 | 402 | -0.5% | 11 | 36 | Township |
| Irving | 25 | 360 | 373 | -0.83% | 401 | 1 | Village |
| Raymond | 26 | 354 | 352 | 0.85% | 10 | 36 | Township |
| Panama | 27 | 319 | 326 | -0.62% | 874 | 0 | Village |
| Walshville | 28 | 310 | 320 | -0.64% | 8 | 37 | Township |
| Fillmore | 29 | 292 | 302 | -0.68% | 440 | 1 | Village |
| Rountree | 30 | 221 | 227 | -0.45% | 6 | 36 | Township |
| Harvel | 31 | 188 | 193 | 0% | 10 | 18 | Township |
| Waggoner | 32 | 180 | 180 | 0% | 738 | 0 | Village |
| Harvel | 33 | 168 | 175 | -1.18% | 233 | 1 | Village |
| Butler | 34 | 162 | 165 | -0.61% | 272 | 1 | Village |
| Donnellson | 35 | 148 | 155 | -1.33% | 399 | 0 | Village |
| Ohlman | 36 | 106 | 110 | -0.93% | 330 | 0 | Village |
| Walshville | 37 | 59 | 62 | -1.67% | 232 | 0 | Village |
Hillsboro is the largest city in Montgomery County, with a population of 6,796.
Walshville is the smallest city in Montgomery County, with a population of 59.
There are 37 cities in Montgomery County, Illinois.