37 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Hillsboro | 1 | 6,769 | 6,941 | -0.4% | 187 | 36 | Township |
| Litchfield | 2 | 6,501 | 6,758 | -0.66% | 726 | 9 | City |
| Hillsboro | 3 | 5,711 | 5,861 | -0.44% | 662 | 9 | City |
| North Litchfield | 4 | 4,762 | 4,942 | -0.58% | 132 | 36 | Township |
| South Litchfield | 5 | 3,176 | 3,283 | -0.5% | 85 | 37 | Township |
| Nokomis | 6 | 2,718 | 2,819 | -0.55% | 75 | 36 | Township |
| Nokomis | 7 | 2,099 | 2,182 | -0.66% | 1,662 | 1 | City |
| East Fork | 8 | 1,965 | 2,040 | -0.66% | 34 | 58 | Township |
| Raymond | 9 | 1,092 | 1,132 | -0.55% | 30 | 36 | Township |
| Witt | 10 | 990 | 1,028 | -0.6% | 27 | 37 | Township |
| Raymond | 11 | 907 | 943 | -0.66% | 722 | 1 | Village |
| Bois D'Arc | 12 | 897 | 928 | -0.44% | 16 | 55 | Township |
| Irving | 13 | 844 | 879 | -0.71% | 25 | 34 | Township |
| Butler | 14 | 838 | 880 | -0.48% | 12 | 72 | Township |
| Witt | 15 | 756 | 786 | -0.66% | 611 | 1 | City |
| Taylor Springs | 16 | 719 | 737 | -0.42% | 682 | 1 | Village |
| Butler Grove | 17 | 708 | 727 | -0.28% | 20 | 36 | Township |
| Farmersville | 18 | 658 | 684 | -0.6% | 931 | 1 | Village |
| Coffeen | 19 | 621 | 642 | -0.48% | 534 | 1 | City |
| Grisham | 20 | 609 | 626 | -0.49% | 25 | 24 | Township |
| Schram City | 21 | 547 | 568 | -0.55% | 966 | 1 | Village |
| Audubon | 22 | 489 | 506 | -0.61% | 9 | 54 | Township |
| Zanesville | 23 | 409 | 424 | -0.49% | 11 | 37 | Township |
| Pitman | 24 | 393 | 402 | -0.51% | 11 | 36 | Township |
| Irving | 25 | 358 | 373 | -0.56% | 399 | 1 | Village |
| Raymond | 26 | 357 | 352 | 0.85% | 10 | 36 | Township |
| Panama | 27 | 318 | 326 | -0.31% | 871 | 0 | Village |
| Walshville | 28 | 308 | 320 | -0.65% | 8 | 37 | Township |
| Fillmore | 29 | 290 | 302 | -0.68% | 437 | 1 | Village |
| Rountree | 30 | 220 | 227 | -0.45% | 6 | 36 | Township |
| Harvel | 31 | 188 | 193 | 0% | 10 | 18 | Township |
| Waggoner | 32 | 180 | 180 | 0% | 738 | 0 | Village |
| Harvel | 33 | 167 | 175 | -0.6% | 232 | 1 | Village |
| Butler | 34 | 162 | 165 | 0% | 272 | 1 | Village |
| Donnellson | 35 | 147 | 155 | -0.68% | 396 | 0 | Village |
| Ohlman | 36 | 105 | 110 | -0.94% | 327 | 0 | Village |
| Walshville | 37 | 59 | 62 | 0% | 232 | 0 | Village |
Hillsboro is the largest city in Montgomery County, with a population of 6,769.
Walshville is the smallest city in Montgomery County, with a population of 59.
There are 37 cities in Montgomery County, Illinois.