24 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| South Kingstown | 1 | 32,121 | 31,925 | 0.08% | 570 | 56 | Town |
| North Kingstown | 2 | 28,035 | 27,708 | 0.35% | 649 | 43 | Town |
| Westerly | 3 | 23,301 | 23,321 | 0.06% | 791 | 29 | Town |
| Westerly | 4 | 18,356 | 17,842 | 0.15% | 1,159 | 16 | CDP |
| Narragansett | 5 | 14,378 | 14,504 | -0.2% | 1,037 | 14 | Town |
| Wakefield-Peace Dale | 6 | 12,458 | 9,772 | 7.15% | 2,527 | 5 | CDP |
| Hopkinton | 7 | 8,443 | 8,399 | 0.14% | 196 | 43 | Town |
| Richmond | 8 | 8,139 | 8,054 | -0.04% | 202 | 40 | Town |
| Charlestown | 9 | 8,052 | 7,992 | 0% | 220 | 37 | Town |
| Exeter | 10 | 6,542 | 6,460 | -0.4% | 114 | 57 | Town |
| Kingston | 11 | 6,456 | 6,407 | -0.54% | 4,146 | 2 | CDP |
| Narragansett Pier | 12 | 2,654 | 3,487 | -1.85% | 744 | 4 | CDP |
| Hope Valley | 13 | 2,358 | 1,888 | 2.17% | 710 | 3 | CDP |
| Charlestown | 14 | 2,128 | 1,392 | 7.15% | 940 | 2 | CDP |
| Ashaway | 15 | 1,706 | 1,444 | 0.83% | 719 | 2 | CDP |
| New Shoreham | 16 | 1,416 | 1,406 | 0.21% | 156 | 9 | Town |
| Carolina | 17 | 1,214 | 882 | 1.34% | 493 | 2 | CDP |
| Bradford | 18 | 1,135 | 1,265 | -1.56% | 625 | 2 | CDP |
| Weekapaug | 19 | 546 | 387 | 1.49% | 469 | 1 | CDP |
| Hopkinton | 20 | 526 | 612 | 7.13% | 159 | 3 | CDP |
| Quonochontaug | 21 | 482 | 422 | 2.12% | 359 | 1 | CDP |
| Misquamicut | 22 | 376 | 378 | -0.27% | 321 | 1 | CDP |
| Watch Hill | 23 | 350 | 196 | 3.86% | 436 | 1 | CDP |
| Wyoming | 24 | 330 | 233 | 1.23% | 383 | 1 | CDP |
South Kingstown is the largest city in Washington County, with a population of 32,121.
Wyoming is the smallest city in Washington County, with a population of 330.
There are 24 cities in Washington County, Rhode Island.