San Juan County Flag

San Juan County

State:
Washington
County Seat:
Friday Harbor

San Juan County's estimated 2026 population is 18,598 with a growth rate of 0.11% in the past year according to the most recent United States census data. San Juan County is the 32nd largest county in Washington. The 2010 population was 15,783 and has seen a growth of 17.84% since that time.

18,598
Total Population
107
Population Density (mi²)
32
Population Rank (State)
21 0.11%
Annual Population Growth

San Juan County Population

Demographics

Economics and Income Statistics