| County | FIPS Code | County Seat | Established in | Population | Area (sq mi) | Area (km2) |
|---|---|---|---|---|---|---|
| Bristol County | 1 | Bristol | 1747 | 49,875 | 24 | 62 |
| Kent County | 3 | East Greenwich | 1750 | 166,158 | 168 | 435 |
| Newport County | 5 | Newport | 1703 | 82,888 | 102 | 264 |
| Providence County | 7 | Providence | 1703 | 626,667 | 409 | 1,059 |
| Washington County | 9 | South Kingstown* | 1729 | 126,979 | 329 | 852 |
