| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Litchfield | 1 | 6,559 | 6,757 | -0.59% | 732 | 9 | City |
| Hillsboro | 2 | 6,199 | 5,871 | 0.24% | 718 | 9 | City |
| Nokomis | 3 | 2,121 | 2,182 | -0.56% | 1,679 | 1 | City |
| Raymond | 4 | 914 | 942 | -0.65% | 727 | 1 | Village |
| Witt | 5 | 765 | 788 | -0.65% | 618 | 1 | City |
| Taylor Springs | 6 | 724 | 738 | -0.41% | 686 | 1 | Village |
| Farmersville | 7 | 664 | 684 | -0.6% | 939 | 1 | Village |
| Coffeen | 8 | 623 | 642 | -0.64% | 536 | 1 | City |
| Schram City | 9 | 552 | 566 | -0.54% | 975 | 1 | Village |
| Irving | 10 | 362 | 374 | -0.82% | 404 | 1 | Village |
| Panama | 11 | 323 | 331 | -0.62% | 885 | 0 | Village |
| Fillmore | 12 | 293 | 302 | -0.68% | 441 | 1 | Village |
| Waggoner | 13 | 180 | 180 | 0% | 738 | 0 | Village |
| Harvel | 14 | 170 | 175 | -0.58% | 236 | 1 | Village |
| Butler | 15 | 164 | 166 | -0.61% | 275 | 1 | Village |
| Donnellson | 16 | 151 | 155 | -0.66% | 407 | 0 | Village |
| Ohlman | 17 | 106 | 110 | -0.93% | 330 | 0 | Village |
| Walshville | 18 | 63 | 62 | 0% | 248 | 0 | Village |
Litchfield is the largest city in Montgomery County, with a population of 6,559.
Walshville is the smallest city in Montgomery County, with a population of 63.
There are 18 cities in Montgomery County, Illinois.