Founded in 1873, San Juan County is one of 39 counties in the state of Washington. Historically, San Juan County was formed from Whatcom County. The city of Friday Harbor is the county seat. With FIPS code of 55, San Juan County has a population of 17,788 and area of 174 square miles (451 km2).
List of all cities in San Juan County, WA alphabetically
| City/Town | Postal Code | Area Code |
| Anacortes, WA | 98222 | 360/564 |
| Blakely Island, WA | 98222 | 360/564 |
| Deer Harbor, WA | 98243 | 360/564 |
| Doebay, WA | 98279 | 360/564 |
| Eastsound, WA | 98245 | 360/564 |
| Friday Harbor, WA | 98250 | 360/564 |
| Lopez Island, WA | 98261 | 360/564 |
| Olga, WA | 98279 | 360/564 |
| Orcas, WA | 98280 | 360/564 |
| Port Stanley, WA | 98261 | 360/564 |
| Roche Harbor, WA | 98250 | 360/564 |
| San Juan Island, WA | 98250 | 360/564 |
| Shaw Island, WA | 98286 | 360/564 |
| Waldron, WA | 98297 | 360/564 |