24 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| South Kingstown town | 1 | 31,935 | 31,930 | -0.14% | 567 | 56.37 | Town |
| North Kingstown town | 2 | 27,735 | 27,702 | -0.06% | 642 | 43.17 | Town |
| Westerly town | 3 | 23,085 | 23,322 | -0.3% | 783 | 29.47 | Town |
| Westerly | 4 | 18,356 | 17,842 | 0.15% | 1,159 | 15.83 | CDP |
| Narragansett town | 5 | 14,239 | 14,511 | -0.59% | 1,027 | 13.87 | Town |
| Wakefield-Peace Dale | 6 | 12,458 | 9,772 | 7.15% | 2,527 | 4.93 | CDP |
| Hopkinton town | 7 | 8,378 | 8,398 | -0.13% | 195 | 43.01 | Town |
| Richmond town | 8 | 8,113 | 8,056 | -0.12% | 201 | 40.32 | Town |
| Charlestown town | 9 | 8,030 | 7,992 | -0.04% | 220 | 36.54 | Town |
| Exeter town | 10 | 6,523 | 6,462 | -0.44% | 114 | 57.45 | Town |
| Kingston | 11 | 6,456 | 6,407 | -0.54% | 4,146 | 1.56 | CDP |
| Narragansett Pier | 12 | 2,654 | 3,487 | -1.85% | 744 | 3.57 | CDP |
| Hope Valley | 13 | 2,358 | 1,888 | 2.17% | 710 | 3.32 | CDP |
| Charlestown | 14 | 2,128 | 1,392 | 7.15% | 940 | 2.26 | CDP |
| Ashaway | 15 | 1,706 | 1,444 | 0.83% | 719 | 2.37 | CDP |
| New Shoreham town | 16 | 1,396 | 1,403 | -0.29% | 154 | 9.08 | Town |
| Carolina | 17 | 1,214 | 882 | 1.34% | 493 | 2.46 | CDP |
| Bradford | 18 | 1,135 | 1,265 | -1.56% | 625 | 1.82 | CDP |
| Weekapaug | 19 | 546 | 387 | 1.49% | 469 | 1.16 | CDP |
| Hopkinton | 20 | 526 | 612 | 7.13% | 159 | 3.30 | CDP |
| Quonochontaug | 21 | 482 | 422 | 2.12% | 359 | 1.34 | CDP |
| Misquamicut | 22 | 376 | 378 | -0.27% | 321 | 1.17 | CDP |
| Watch Hill | 23 | 350 | 196 | 3.86% | 436 | 0.80 | CDP |
| Wyoming | 24 | 330 | 233 | 1.23% | 383 | 0.86 | CDP |
South Kingstown town is the largest city in Washington County, with a population of 31,935.
Wyoming is the smallest city in Washington County.
There are 24 cities in Washington County, Rhode Island.