1 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Friday Harbor | 1 | 2,800 | 2,631 | 1.01% | 1,280 | 2 | Town |
Friday Harbor is the largest city in San Juan County, with a population of 2,800.
Friday Harbor is the smallest city in San Juan County, with a population of 2,800.
There is 1 city in San Juan County, Washington.