18 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Moses Lake | 1 | 27,352 | 25,434 | 1.42% | 1,508 | 18 | City |
| Ephrata | 2 | 8,774 | 8,492 | 0.64% | 837 | 10 | City |
| Quincy | 3 | 8,459 | 7,634 | 1.99% | 1,350 | 6 | City |
| Moses Lake North | 4 | 5,093 | 4,664 | 0.89% | 890 | 6 | CDP |
| Mattawa | 5 | 3,893 | 3,348 | 2.88% | 3,889 | 1 | City |
| Cascade Valley | 6 | 3,760 | 3,234 | 2.76% | 1,012 | 4 | CDP |
| Desert Aire | 7 | 2,986 | 2,716 | 3.14% | 879 | 3 | CDP |
| Warden | 8 | 2,893 | 2,457 | 3.1% | 986 | 3 | City |
| Royal City | 9 | 1,937 | 1,784 | 1.57% | 1,664 | 1 | City |
| Soap Lake | 10 | 1,799 | 1,701 | 1.07% | 1,170 | 2 | City |
| Lakeview | 11 | 1,696 | 1,013 | 3.16% | 1,506 | 1 | CDP |
| George | 12 | 1,055 | 807 | 4.87% | 766 | 1 | City |
| Electric City | 13 | 957 | 957 | 0% | 481 | 2 | City |
| Grand Coulee | 14 | 956 | 973 | -0.42% | 761 | 1 | City |
| Coulee City | 15 | 555 | 550 | 0.18% | 601 | 1 | Town |
| Schwana | 16 | 439 | 669 | 7.07% | 1,749 | 0 | CDP |
| Wilson Creek | 17 | 203 | 207 | -0.49% | 210 | 1 | Town |
| Hartline | 18 | 176 | 179 | -0.56% | 527 | 0 | Town |
Moses Lake is the largest city in Grant County, with a population of 27,352.
Hartline is the smallest city in Grant County, with a population of 176.
There are 18 cities in Grant County, Washington.