Polk County Flag

Polk County

State:
Iowa
County Seat:
Des Moines

Polk County's 2026 population is estimated at 533,581, reflecting a 1.66% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). Polk County is the largest county in Iowa. The 2010 population was 432,360 and has grown 23.41% since 2010.

533,581
Total Population
933
Population Density (mi²)
1
Population Rank (State)
8.7K 1.66%
Annual Population Growth

Polk County Population

Demographics

Economics and Income Statistics