Iowa Counties, Demographics & Geography
Complete official guide to all 99 counties in Iowa (IA). Explore 2024 US Census population estimates, county seats, FIPS codes, land areas, and interactive mapping tools powered by GeoMap Suite.
Iowa County Breakdown
Showing 7 of 7 documented counties and seats.
County Name | FIPS | County Seat | Population (Census) | Land Area | Quick Tool |
|---|---|---|---|---|---|
| Polk County | 19153 | Des Moines | 492,401 | 570 sq mi | Lookup |
| Linn County | 19113 | Cedar Rapids | 230,299 | 717 sq mi | Lookup |
| Scott County | 19163 | Davenport | 174,669 | 458 sq mi | Lookup |
| Johnson County | 19103 | Iowa City | 152,854 | 614 sq mi | Lookup |
| Black Hawk County | 19013 | Waterloo | 131,144 | 565 sq mi | Lookup |
| Woodbury County | 19193 | Sioux City | 105,941 | 873 sq mi | Lookup |
| Dubuque County | 19061 | Dubuque | 99,266 | 608 sq mi | Lookup |
Geographic Structure of Iowa Counties
County Administration & Governance
In Iowa, county governments manage vital public infrastructure, tax assessments, law enforcement, judicial courts, election administration, and public records. The county seat (Des Moines and other municipal headquarters) houses the primary courthouse, commissioners, and sheriff’s department.
All Iowa counties carry a unique 5-digit Federal Information Processing Standard (FIPS) code, where the first two digits (19) designate the state and the remaining three digits identify each specific jurisdiction.
Geographic & Demographic Highlights
- Most Populous County:Polk County (492,401 residents)
- Largest by Land Area:Woodbury County (873 sq mi)
- State Capital:Des Moines
- Census Bureau Region:Midwest United States
Demographic calculations derive from the United States Census Bureau 2024 Population Estimates Program (PEP) and TIGER/Line geographic boundary files.