18 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Litchfield | 1 | 6,501 | 6,758 | -0.66% | 726 | 9 | City |
| Hillsboro | 2 | 5,711 | 5,861 | -0.44% | 662 | 9 | City |
| Nokomis | 3 | 2,099 | 2,182 | -0.66% | 1,662 | 1 | City |
| Raymond | 4 | 907 | 943 | -0.66% | 722 | 1 | Village |
| Witt | 5 | 756 | 786 | -0.66% | 611 | 1 | City |
| Taylor Springs | 6 | 719 | 737 | -0.42% | 682 | 1 | Village |
| Farmersville | 7 | 658 | 684 | -0.6% | 931 | 1 | Village |
| Coffeen | 8 | 621 | 642 | -0.48% | 534 | 1 | City |
| Schram City | 9 | 547 | 568 | -0.55% | 966 | 1 | Village |
| Irving | 10 | 358 | 373 | -0.56% | 399 | 1 | Village |
| Panama | 11 | 318 | 326 | -0.31% | 871 | 0 | Village |
| Fillmore | 12 | 290 | 302 | -0.68% | 437 | 1 | Village |
| Waggoner | 13 | 180 | 180 | 0% | 738 | 0 | Village |
| Harvel | 14 | 167 | 175 | -0.6% | 232 | 1 | Village |
| Butler | 15 | 162 | 165 | 0% | 272 | 1 | Village |
| Donnellson | 16 | 147 | 155 | -0.68% | 396 | 0 | Village |
| Ohlman | 17 | 105 | 110 | -0.94% | 327 | 0 | Village |
| Walshville | 18 | 59 | 62 | 0% | 232 | 0 | Village |
Litchfield is the largest city in Montgomery County, with a population of 6,501.
Walshville is the smallest city in Montgomery County, with a population of 59.
There are 18 cities in Montgomery County, Illinois.