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Marion County, OR Demographics

Marion County, OR is the 5th most populous of 36 counties in Oregon, with 345,920 residents across 1,181 square miles. That is about 293 people per square mile.

At the 2020 census

Population 345,920
Land area 1,181 sq mi
Density 293 / 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, OR

Measured from the county's main population center using 2020 census blocks.

We're computing the drive-time and radius areas around Marion County, OR — check back shortly. Meanwhile you can drop a pin anywhere in the radius tool.

Census tracts in Marion County, OR

Name Population Sq mi Per sq mi
Census Tract 18.02 9,033 3.3 2,734
Census Tract 107.01 8,447 5.6 1,511
Census Tract 23.03 8,334 1.4 6,147
Census Tract 16.01 8,107 1.6 5,113
Census Tract 102.02 7,972 23.2 344
Census Tract 107.02 7,452 75.0 99
Census Tract 16.03 7,269 5.0 1,448
Census Tract 18.01 7,073 1.3 5,439
Census Tract 103.04 6,893 1.3 5,232
Census Tract 23.04 6,799 2.1 3,176
Census Tract 22.02 6,713 1.6 4,318
Census Tract 105.02 6,683 1.9 3,483
Census Tract 17.01 6,588 1.0 6,786
Census Tract 14.01 6,495 3.1 2,099
Census Tract 108.02 6,434 41.9 154
Census Tract 21.02 6,420 1.2 5,404
Census Tract 25.02 6,284 46.5 135
Census Tract 103.07 6,213 2.9 2,162
Census Tract 27.01 6,195 21.1 293
Census Tract 108.01 6,171 43.6 141
Census Tract 15.02 6,110 1.1 5,495
Census Tract 105.01 6,067 152.7 40
Census Tract 14.02 5,960 1.0 6,001
Census Tract 5.02 5,926 0.6 9,149
Census Tract 103.09 5,770 0.6 9,067
Census Tract 16.06 5,738 0.7 7,653
Census Tract 17.02 5,684 0.8 7,358
Census Tract 9 5,584 0.8 7,095
Census Tract 20.02 5,566 1.3 4,324
Census Tract 20.01 5,476 1.2 4,551
Census Tract 7.02 5,457 1.0 5,286
Census Tract 18.03 5,436 6.1 894
Census Tract 25.03 5,429 1.0 5,189
Census Tract 15.03 5,279 0.9 5,958
Census Tract 6 5,260 0.8 6,390
Census Tract 11 5,060 0.9 5,681
Census Tract 3 4,993 0.8 6,181
Census Tract 104 4,975 30.8 162
Census Tract 103.03 4,972 38.0 131
Census Tract 16.08 4,897 0.6 8,005
Census Tract 16.05 4,874 0.4 11,958
Census Tract 4 4,808 2.0 2,352
Census Tract 17.03 4,675 2.9 1,600
Census Tract 15.01 4,658 1.2 3,966
Census Tract 2 4,595 1.2 3,799
Census Tract 16.07 4,577 0.7 6,532
Census Tract 103.05 4,576 7.3 629
Census Tract 28 4,471 19.0 236
Census Tract 10 4,425 5.3 832
Census Tract 23.01 4,380 1.4 3,119
Census Tract 13 4,310 2.6 1,639
Census Tract 105.03 4,302 39.0 110
Census Tract 25.04 4,296 0.9 4,579
Census Tract 24 4,281 11.8 361
Census Tract 103.08 4,261 1.1 3,852
Census Tract 5.01 3,878 0.9 4,323
Census Tract 12 3,700 0.9 4,233
Census Tract 27.02 3,619 18.7 193
Census Tract 102.01 2,718 21.1 129
Census Tract 106 2,661 429.1 6
Census Tract 7.03 2,460 0.4 6,074
Census Tract 21.01 2,455 0.4 6,089
Census Tract 22.01 2,136 0.5 4,061
Census Tract 26 2,084 36.4 57
Census Tract 101 1,506 49.1 31

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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.

Read how BlockAtlas computes population within an area →