| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Moses Lake | 1 | 27,859 | 25,432 | 1.42% | 1,536 | 18 | City |
| Ephrata | 2 | 8,893 | 8,490 | 0.67% | 849 | 10 | City |
| Quincy | 3 | 8,673 | 7,634 | 1.92% | 1,297 | 7 | City |
| Mattawa | 4 | 3,984 | 3,355 | 2.84% | 3,980 | 1 | City |
| Warden | 5 | 2,917 | 2,462 | 3.07% | 995 | 3 | City |
| Royal City | 6 | 1,927 | 1,790 | 1.64% | 1,655 | 1 | City |
| Soap Lake | 7 | 1,836 | 1,704 | 1.05% | 1,195 | 2 | City |
| George | 8 | 1,073 | 807 | 4.79% | 779 | 1 | City |
| Electric City | 9 | 954 | 958 | 0% | 480 | 2 | City |
| Grand Coulee | 10 | 943 | 975 | -0.42% | 751 | 1 | City |
| Coulee City | 11 | 551 | 550 | 0.18% | 596 | 1 | Town |
| Wilson Creek | 12 | 203 | 207 | -0.49% | 210 | 1 | Town |
| Hartline | 13 | 174 | 179 | -0.57% | 521 | 0 | Town |
Moses Lake is the largest city in Grant County, with a population of 27,859.
Hartline is the smallest city in Grant County, with a population of 174.
There are 13 cities in Grant County, Washington.