16 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Beardstown | 1 | 6,542 | 6,706 | -0.5% | 255 | 26 | Township |
| Beardstown | 2 | 5,772 | 5,924 | -0.53% | 1,595 | 4 | City |
| Virginia | 3 | 1,617 | 1,666 | -0.55% | 45 | 36 | Township |
| Virginia | 4 | 1,460 | 1,507 | -0.68% | 1,210 | 1 | City |
| Ashland | 5 | 1,250 | 1,287 | -0.64% | 70 | 18 | Township |
| Ashland | 6 | 1,181 | 1,215 | -0.59% | 1,579 | 1 | Village |
| Bluff Springs | 7 | 860 | 880 | -0.46% | 15 | 58 | Township |
| Arenzville | 8 | 740 | 758 | -0.4% | 20 | 37 | Township |
| Chandlerville | 9 | 516 | 528 | -0.58% | 650 | 1 | Village |
| Chandlerville | 10 | 445 | 453 | -0.22% | 18 | 25 | Township |
| Arenzville | 11 | 356 | 366 | -0.56% | 464 | 1 | Village |
| Sangamon Valley | 12 | 324 | 333 | -0.61% | 8 | 40 | Township |
| Hagener | 13 | 317 | 330 | -1.25% | 7 | 48 | Township |
| Panther Creek | 14 | 294 | 301 | -0.34% | 8 | 36 | Township |
| Philadelphia | 15 | 193 | 196 | -0.52% | 5 | 36 | Township |
| Newmansville | 16 | 65 | 66 | 0% | 4 | 18 | Township |
Beardstown is the largest city in Cass County, with a population of 6,542.
Newmansville is the smallest city in Cass County, with a population of 65.
There are 16 cities in Cass County, Illinois.