Coos County Flag

Coos County

State:
New Hampshire
County Seat:
Lancaster

Coos County's 2026 population is estimated at 31,309, reflecting a -0.11% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). Coos County is the 10th largest county in New Hampshire. The 2010 population was 32,970 and has grown -5.04% since 2010.

31,309
Total Population
17
Population Density (mi²)
10
Population Rank (State)
-34 -0.11%
Annual Population Growth

Coos County Population

Demographics

Economics and Income Statistics