17 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Gold Hill township | 1 | 1,271 | 1,440 | -3.49% | 36 | 34.99 | Township |
| Shawneetown | 2 | 955 | 1,052 | -1.95% | 1,301 | 0.73 | City |
| Ridgway | 3 | 780 | 852 | -1.76% | 886 | 0.88 | Village |
| Ridgway township | 4 | 749 | 850 | -3.48% | 21 | 35.50 | Township |
| Equality township | 5 | 679 | 772 | -3.55% | 18 | 36.84 | Township |
| Equality | 6 | 484 | 534 | -2.02% | 552 | 0.88 | Village |
| New Haven township | 7 | 394 | 443 | -3.19% | 9 | 43.69 | Township |
| North Fork township | 8 | 387 | 429 | -2.76% | 11 | 36.50 | Township |
| Omaha township | 9 | 364 | 417 | -3.7% | 20 | 18.60 | Township |
| New Haven | 10 | 363 | 397 | -1.89% | 292 | 1.24 | Village |
| Omaha | 11 | 186 | 208 | -2.11% | 250 | 0.74 | Village |
| Shawnee township | 12 | 153 | 171 | -3.16% | 6 | 23.54 | Township |
| Eagle Creek township | 13 | 144 | 162 | -3.36% | 4 | 36.92 | Township |
| Bowlesville township | 14 | 133 | 149 | -2.92% | 3 | 38.53 | Township |
| Old Shawneetown | 15 | 105 | 114 | -1.87% | 206 | 0.51 | Village |
| Asbury township | 16 | 90 | 102 | -3.23% | 5 | 17.83 | Township |
| Junction | 17 | 51 | 56 | -1.92% | 62 | 0.83 | Village |
Gold Hill township is the largest city in Gallatin County, with a population of 1,271.
Junction is the smallest city in Gallatin County.
There are 17 cities in Gallatin County, Illinois.