16 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Beardstown | 1 | 6,509 | 6,706 | -0.5% | 254 | 26 | Township |
| Beardstown | 2 | 5,742 | 5,924 | -0.52% | 1,587 | 4 | City |
| Virginia | 3 | 1,608 | 1,666 | -0.56% | 45 | 36 | Township |
| Virginia | 4 | 1,451 | 1,507 | -0.62% | 1,202 | 1 | City |
| Ashland | 5 | 1,242 | 1,287 | -0.64% | 69 | 18 | Township |
| Ashland | 6 | 1,174 | 1,215 | -0.59% | 1,570 | 1 | Village |
| Bluff Springs | 7 | 856 | 880 | -0.47% | 15 | 58 | Township |
| Arenzville | 8 | 737 | 758 | -0.41% | 20 | 37 | Township |
| Chandlerville | 9 | 514 | 528 | -0.39% | 647 | 1 | Village |
| Chandlerville | 10 | 444 | 453 | -0.22% | 18 | 25 | Township |
| Arenzville | 11 | 354 | 366 | -0.56% | 461 | 1 | Village |
| Sangamon Valley | 12 | 322 | 333 | -0.62% | 8 | 40 | Township |
| Hagener | 13 | 313 | 330 | -1.26% | 7 | 48 | Township |
| Panther Creek | 14 | 293 | 301 | -0.34% | 8 | 36 | Township |
| Philadelphia | 15 | 192 | 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 6,509.
Newmansville is the smallest city in Cass County, with a population of 65.
There are 16 cities in Cass County, Illinois.