18 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Moses Lake | 1 | 26,933 | 25,348 | 1.19% | 1,485 | 18.14 | City |
| Ephrata | 2 | 8,777 | 8,496 | 0.64% | 838 | 10.48 | City |
| Quincy | 3 | 8,770 | 7,632 | 2.67% | 1,399 | 6.27 | City |
| Moses Lake North | 4 | 5,093 | 4,664 | 0.89% | 890 | 5.72 | CDP |
| Mattawa | 5 | 4,040 | 3,342 | 3.59% | 4,036 | 1 | City |
| Cascade Valley | 6 | 3,760 | 3,234 | 2.76% | 1,012 | 3.71 | CDP |
| Desert Aire | 7 | 2,986 | 2,716 | 3.14% | 879 | 3.40 | CDP |
| Warden | 8 | 2,809 | 2,454 | 2.59% | 958 | 2.93 | City |
| Royal City | 9 | 1,971 | 1,785 | 1.91% | 1,693 | 1.16 | City |
| Soap Lake | 10 | 1,773 | 1,700 | 0.85% | 1,154 | 1.54 | City |
| Lakeview | 11 | 1,696 | 1,013 | 3.16% | 1,506 | 1.13 | CDP |
| Grand Coulee | 12 | 946 | 975 | -0.63% | 753 | 1.26 | City |
| Electric City | 13 | 938 | 958 | -0.42% | 472 | 1.99 | City |
| George | 14 | 936 | 808 | 2.86% | 679 | 1.38 | City |
| Coulee City | 15 | 551 | 550 | 0% | 596 | 0.92 | Town |
| Schwana | 16 | 439 | 669 | 7.07% | 1,749 | 0.25 | CDP |
| Wilson Creek | 17 | 200 | 205 | -0.5% | 207 | 0.97 | Town |
| Hartline | 18 | 175 | 179 | -0.57% | 524 | 0.33 | Town |
Moses Lake is the largest city in Grant County, with a population of 26,933.
Hartline is the smallest city in Grant County.
There are 18 cities in Grant County, Washington.