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 distinguished by its share of foreign-born residents, 54.0% of the population. Washington County is a county in Idaho with a population of 10,866. It ranks #29 among counties in Idaho by population.
Earnings trail the nation, with the median household making $53,608, below the US median of $78,538. Poverty runs at 11.1%, below the national 12.4%. Home values run above average at $250,300, with typical rent around $919.
19.0% of adults 25 and older hold a bachelor’s degree, below the national average of 35.0%. Remote work is below the national 14.0% at 6.6%, and the average commute runs about 18 minutes each way.
The large foreign-born share is a defining thread in Washington County, shaping language, household composition, and the labor force behind the economic figures above.
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.