4 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Metropolis | 1 | 5,668 | 5,953 | -1% | 942 | 6 | City |
| Brookport | 2 | 675 | 722 | -1.32% | 1,034 | 1 | City |
| Joppa | 3 | 323 | 347 | -1.52% | 665 | 0 | Village |
| New Grand Chain | 4 | 141 | 153 | -1.4% | 135 | 1 | Village |
Metropolis is the largest city in Massac County, with a population of 5,668.
New Grand Chain is the smallest city in Massac County, with a population of 141.
There are 4 cities in Massac County, Illinois.