Ranking of Oregon Counties By Percentage of Population Aged 25 years and above with an Educational attainment of Less than High School Diploma in 2021 (ACS-5Yrs)

Updated on September 3, 2025.

Based on the US Census ACS-5Yrs estimates, in 2021, the percentage of the population of Oregon (aged 25 years and above) who had an educational attainment of Less than High School Diploma was 8.50%. Among all Oregon counties, Morrow County had the highest percentage of its population (aged 25 years and above) with an educational attainment of Less than High School Diploma (22.54%), followed by Malheur County (18.51%), and Umatilla County (16.76%).

The chart below shows the top 10 Oregon counties, and the table below shows the ranking of all Oregon counties.

You can see similar information for other educational attainments.

You can also see similar information for other states and for the United States.

Ranking of Oregon Counties By Percentage of Population (Aged 25yrs+) with an Educational Attainment of Less than High School Diploma in 2021
Morrow County
Malheur County
Umatilla County
Hood River County
Marion County
Lake County
Wasco County
Sherman County
Jefferson County
Klamath County
Ranking of Oregon Counties By Percentage of Population (Aged 25yrs+) with an Educational Attainment of Less than High School Diploma in 2021
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Rank County Percentage of Population (Aged 25yrs+) (%)
1 Morrow County 22.54
2 Malheur County 18.51
3 Umatilla County 16.76
4 Hood River County 16.75
5 Marion County 14.33
6 Lake County 13.95
7 Wasco County 12.98
8 Sherman County 12.69
9 Jefferson County 12.16
10 Klamath County 11.63
11 Wheeler County 10.40
12 Coos County 10.04
13 Yamhill County 9.89
14 Linn County 9.82
15 Columbia County 9.55
16 Douglas County 9.46
16 Grant County 9.46
17 Tillamook County 9.33
18 Harney County 9.32
19 Baker County 9.22
20 Josephine County 9.19
21 Crook County 9.16
22 Jackson County 9.13
23 Polk County 8.43
24 Curry County 8.09
25 Clatsop County 7.87
26 Multnomah County 7.63
27 Lincoln County 7.26
28 Union County 7.25
29 Lane County 7.11
30 Washington County 7.01
31 Gilliam County 6.56
32 Wallowa County 5.99
33 Deschutes County 5.67
34 Clackamas County 5.66
35 Benton County 3.71