21 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Marmarth | 1 | 92 | 100 | -2.13% | 36 | 3 | City |
| Rainy Butte | 2 | 35 | 38 | -2.78% | 1 | 36 | Township |
| Sand Creek | 3 | 33 | 36 | -2.94% | 0.00 | 71 | Township |
| Woodberry | 4 | 32 | 34 | 0% | 1 | 36 | Township |
| Cash | 5 | 30 | 37 | -11.76% | 1 | 36 | Township |
| Connor | 6 | 30 | 33 | -3.23% | 1 | 36 | Township |
| Cedar Creek | 7 | 28 | 29 | -3.45% | 1 | 36 | Township |
| Moord | 8 | 28 | 31 | -3.45% | 1 | 35 | Township |
| Hume | 9 | 22 | 25 | -4.35% | 1 | 36 | Township |
| Mineral Springs | 10 | 22 | 25 | -4.35% | 1 | 36 | Township |
| Amidon | 11 | 21 | 24 | -4.55% | 33 | 1 | City |
| Crawford | 12 | 21 | 22 | 0% | 1 | 36 | Township |
| Peaceful Valley | 13 | 20 | 21 | 0% | 1 | 37 | Township |
| Sheets | 14 | 19 | 20 | 0% | 1 | 36 | Township |
| Mound | 15 | 17 | 18 | 0% | 0.00 | 36 | Township |
| Bucklin | 16 | 15 | 16 | 0% | 0.00 | 32 | Township |
| Carroll | 17 | 13 | 14 | 0% | 0.00 | 36 | Township |
| White Lake | 18 | 9 | 11 | -10% | 0.00 | 36 | Township |
| Hughes | 19 | 6 | 8 | -14.29% | 0.00 | 35 | Township |
| Richland Center | 20 | 5 | 5 | 0% | 0.00 | 36 | Township |
| Harper | 21 | 0 | 0 | 0.00 | 36 | Township |
Marmarth is the largest city in Slope County, with a population of 92.
Harper is the smallest city in Slope County, with a population of 0.
There are 21 cities in Slope County, North Dakota.