Washington County, Idaho Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 29th-largest in Idaho
The population of Washington County, Idaho is 10,866 as of the 2023 American Community Survey, making it the 29th-largest county in Idaho. The median household income is $53,608, the median home value is $250,300, and the median age is 44.6.
The population of Washington County has grown 13.4% since 2010 (10,177 → 11,539), a +0.90% annualized rate.
10,866
Population
+0.90%
Annual growth
7
People / sq mi
$53,608
Median Income
$250,300
Median Home Value
Washington County covers 1,453 sq mi of land at 7.5 people per square mile.
About Washington County, ID
Washington County is a county in Idaho with a population of 10,866. It ranks #29 among counties in Idaho by population. The median age is 44.6, older than the national median. The population is 49.4% male and 50.6% female.
The median household income in Washington County is $53,608, below the US median of $74,580. 11.1% of residents live below the federal poverty level. Home values sit at a median of $250,300, with monthly rent averaging $919. The homeownership rate of 73.3% is higher than the national rate of 64.8%.
Educational attainment in Washington County reflects 19.0% of adults 25 and older holding a bachelor's degree or higher, below the national average of 34.3%. Roughly 6.6% of workers primarily work from home, below the national work-from-home rate of 14.2%. The average commute is 18.3 minutes each way.
Washington County Population History (2010-2024)
The county of Washington County had a population of 10,177 in 2010 and 11,539 in 2024, a 13.4% growth over 14 years. The peak was 11,539 in 2024. Average annual growth rate: 0.91%.
11,539
Population (2024)
10,177
Population (2010)
11,539
Peak (2024)
0.91%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 10,177 |
| 2011 | 10,135 |
| 2012 | 10,028 |
| 2013 | 9,916 |
| 2014 | 9,956 |
| 2015 | 9,894 |
| 2016 | 10,030 |
| 2017 | 10,055 |
| 2018 | 10,070 |
| 2019 | 10,126 |
| 2020 | 10,560 |
| 2021 | 10,905 |
| 2022 | 11,198 |
| 2023 | 11,508 |
| 2024 | 11,539 |
Race & Ethnicity
| White | 83.3% |
| Black or African American | 0.1% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 4.2% |
| Two or More Races | 0.0% |
Age & Sex
44.6
Median Age
50.6%
Female
49.4%
Male
25.7%
Age 65+
Age Distribution
Children (under 15): 18.7% · Seniors (65+): 25.7%
Income & Poverty
| Median household income | $53,608$-21,028 vs state |
| Mean household income | $69,532 |
| Per-capita income | $27,769 |
| Poverty rate | 11.1%+4.1% vs state |
| Unemployment rate | 2.2% |
| Employment-to-population | 44.9% |
Top Industries by Employment
The largest employment sector in Washington County is professional & business services, accounting for 23.5% of workers.
How residents commute
0.5%
Drive alone
4.9%
Carpool
73.1%
Public transit
6.6%
Work from home
18.3 min
Avg commute
Housing
$250,300$-125,700 vs state
Median home value
$919
Median rent
73.3%
Homeownership rate
4,586
Total housing units
89.2%
Occupied
10.8%
Vacant
26.7%
Renter-occupied
Social & access
90.2%
With health insurance
90.7%
With broadband internet
54.0%
Foreign-born
8.7%
Veterans (18+)
17.0%
With a disability
87.1%
Speak language other than English at home
Education
88.7%
High School+
19.0%
Bachelor's+
Largest cities in Idaho
Other counties in Idaho
Part of Idaho
Metro areas in Idaho
County rankings
Frequently Asked Questions
Washington County, Idaho has a population of 10,866 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 29th-largest county in Idaho. Population density is 7 people per square mile.
The population of Washington County has grown 13.4% since 2010 (10,177 → 11,539), a +0.90% annualized rate.
The median household income in Washington County, Idaho is $53,608, with mean (average) household income of $69,532 and per-capita income of $27,769. 11.1% of residents live below the federal poverty level.
In Washington County, the largest racial and ethnic groups are White (83.3%), Hispanic or Latino (4.2%), Black or African American (0.1%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Washington County, Idaho is 44.6 years. Residents are 50.6% female and 49.4% male.
The median home value in Washington County is $250,300 and median monthly rent is $919. 73.3% of occupied housing units are owner-occupied. The county has 4,586 total housing units, 10.8% of which are vacant.
The largest employment sector in Washington County, Idaho is professional, scientific, and management services, employing 23.5% of workers. The unemployment rate is 2.2%.
Boise City is among the largest cities associated with Washington County, Idaho, with a population of 235,701.
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Statewide data for Idaho
Population, race, income, age, and trends across Idaho
Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.