4 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Metropolis | 1 | 5,731 | 5,953 | -0.78% | 952 | 6 | City |
| Brookport | 2 | 683 | 721 | -1.16% | 1,046 | 1 | City |
| Joppa | 3 | 328 | 350 | -1.5% | 675 | 0 | Village |
| New Grand Chain | 4 | 143 | 155 | -2.05% | 137 | 1 | Village |
Metropolis is the largest city in Massac County, with a population of 5,731.
New Grand Chain is the smallest city in Massac County, with a population of 143.
There are 4 cities in Massac County, Illinois.