15 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Morgantown | 1 | 30,598 | 30,068 | 0.35% | 3,006 | 10 | City |
| Morgantown | 2 | 30,598 | 30,056 | 0.35% | 3,006 | 10 | City |
| Cheat Lake | 3 | 10,546 | 9,559 | 1.65% | 735 | 14 | CDP |
| Brookhaven | 4 | 6,814 | 6,293 | 1.64% | 737 | 9 | CDP |
| Westover | 5 | 4,117 | 3,968 | 0.71% | 1,352 | 3 | City |
| Westover | 6 | 4,117 | 3,972 | 0.71% | 1,352 | 3 | City |
| Star City | 7 | 1,811 | 1,766 | 0.44% | 3,703 | 0 | Town |
| Star City | 8 | 1,811 | 1,768 | 0.44% | 3,703 | 0 | Town |
| Cassville | 9 | 1,787 | 1,042 | 4.2% | 504 | 4 | CDP |
| Granville | 10 | 1,383 | 1,355 | 0.36% | 1,066 | 1 | Town |
| Granville | 11 | 1,383 | 1,355 | 0.36% | 1,066 | 1 | Town |
| Booth | 12 | 398 | 560 | 7.28% | 725 | 1 | CDP |
| Blacksville | 13 | 119 | 117 | 0% | 398 | 0 | Town |
| Blacksville | 14 | 119 | 117 | 0% | 398 | 0 | Town |
| Osage | 15 | 55 | 170 | 7.84% | 304 | 0 | CDP |
Morgantown is the largest city in Monongalia County, with a population of 30,598.
Osage is the smallest city in Monongalia County, with a population of 55.
There are 15 cities in Monongalia County, West Virginia.