Marion County, IA Demographics
Marion County, IA is the 22nd most populous of 99 counties in Iowa, with 33,414 residents across 554 square miles. That is about 60 people per square mile.
At the 2020 census
| Population | 33,414 |
|---|---|
| Land area | 554 sq mi |
| Density | 60 / sq mi |
Data: 2020 Census · American Community Survey 2024
How Marion County compares to the US
We're computing this county's comparison table — check back shortly. Population, land area, and density above are already exact.
Central Location: Marion County, IA
Measured from the county's main population center using 2020 census blocks.
We're computing the drive-time and radius areas around Marion County, IA — check back shortly. Meanwhile you can drop a pin anywhere in the radius tool.
Census tracts in Marion County, IA
| Name | Population | Sq mi | Per sq mi |
|---|---|---|---|
| Census Tract 301.01 | 5,025 | 139.2 | 36 |
| Census Tract 304.01 | 4,855 | 58.8 | 83 |
| Census Tract 302.01 | 3,811 | 5.5 | 694 |
| Census Tract 304.02 | 3,758 | 53.7 | 70 |
| Census Tract 302.02 | 3,166 | 2.6 | 1,206 |
| Census Tract 303 | 2,930 | 2.5 | 1,153 |
| Census Tract 301.02 | 2,815 | 60.2 | 47 |
| Census Tract 306 | 2,527 | 117.3 | 22 |
| Census Tract 307 | 2,527 | 114.0 | 22 |
| Census Tract 305 | 2,000 | 0.5 | 3,670 |
Related places
Other counties nearby
Nearest counties
Metro areas containing Marion County
About this page
This page shows demographics for a US county from the 2020 census and the American Community Survey: population, land area, density, urban share, and how the county compares to national averages for income, housing, age, and more.
Counties subdivide into census tracts, listed below with their populations. The drive-time and radius tables measure the population around the county's main population center.