9 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 |
| Narragansett | 4 | 14,378 | 14,504 | -0.2% | 1,037 | 14 | Town |
| Hopkinton | 5 | 8,443 | 8,399 | 0.14% | 196 | 43 | Town |
| Richmond | 6 | 8,139 | 8,054 | -0.04% | 202 | 40 | Town |
| Charlestown | 7 | 8,052 | 7,992 | 0% | 220 | 37 | Town |
| Exeter | 8 | 6,542 | 6,460 | -0.4% | 114 | 57 | Town |
| New Shoreham | 9 | 1,416 | 1,406 | 0.21% | 156 | 9 | Town |
South Kingstown is the largest city in Washington County, with a population of 32,121.
New Shoreham is the smallest city in Washington County, with a population of 1,416.
There are 9 cities in Washington County, Rhode Island.