Polk County, Iowa

Polk County, Iowa
The Polk County Courthouse in Des Moines
Location within the U.S. state of Iowa
Coordinates: 41°41′05″N 93°34′08″W / 41.684816°N 93.568971°W / 41.684816; -93.568971
Country United States
State Iowa
FoundedJanuary 13, 1846 (created)
March 1, 1846 (organized)
Named afterJames K. Polk
SeatDes Moines
Largest cityDes Moines
Area
 • Total
591.888 sq mi (1,532.98 km2)
 • Land572.720 sq mi (1,483.34 km2)
 • Water19.168 sq mi (49.64 km2)  3.24%
Population
 (2020)
 • Total
492,401
 • Estimate 
(2024)
516,185
 • Density859.759/sq mi (331.955/km2)
Time zoneUTC−6 (Central)
 • Summer (DST)UTC−5 (CDT)
Area code515
Congressional district3rd
Websitepolkcountyiowa.gov
  • Iowa county number 77

Polk County is a county located in the U.S. state of Iowa. As of the 2020 census, the population was 492,401, and was estimated to be 516,185 in 2024, making it the most populous county in Iowa. The county seat and the largest city is Des Moines, which is also the capital city of Iowa. Polk County is included in the Des Moines–West Des Moines, IA Metropolitan Statistical Area.