San Juan County Flag

San Juan County

State:
Washington
County Seat:
Friday Harbor

San Juan County's 2026 population is estimated at 18,794, reflecting a 0.34% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). San Juan County is the 32nd largest county in Washington. The 2010 population was 15,783 and has grown 19.08% since 2010.

18,794
Total Population
108
Population Density (mi²)
32
Population Rank (State)
63 0.34%
Annual Population Growth

San Juan County Population

Demographics

Economics and Income Statistics