Knox County, Maine Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 10th-largest in Maine
The population of Knox County, Maine is 40,860 as of the 2023 American Community Survey, making it the 10th-largest county in Maine. The median household income is $71,903, the median home value is $290,800, and the median age is 49.2.
The population of Knox County has grown 3.2% since 2010 (39,727 → 40,981), a +0.22% annualized rate.
40,860
Population
+0.22%
Annual growth
112
People / sq mi
$71,903
Median Income
$290,800
Median Home Value
Knox County covers 365 sq mi of land at 112.0 people per square mile.
About Knox County, ME
The poverty rate is what most separates Knox County from the typical county: 4.1% of residents live below the federal poverty line, against 12.4% nationally. With 40,860 residents, Knox County is a county in Maine. That makes it one of the ten largest counties in Maine in the country, at #10 by population.
Median household income is $71,903, below the US median of $78,538. Poverty is among the lowest of comparable US counties, at 4.1% — below the national 12.4%. The median home value is $290,800, with typical rent around $1,079.
Degree attainment is near the top of the range for US counties: 39.1% of adults 25+ hold a bachelor’s, above the 35.0% national rate. A solid 14.5% of workers are based at home, close to the national 14.0%, and the average commute runs about 20 minutes each way.
Knox County Population History (2010-2024)
The county of Knox County had a population of 39,727 in 2010 and 40,981 in 2024, a 3.2% growth over 14 years. The peak was 41,251 in 2022. Average annual growth rate: 0.22%.
40,981
Population (2024)
39,727
Population (2010)
41,251
Peak (2022)
0.22%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 39,727 |
| 2011 | 39,674 |
| 2012 | 39,613 |
| 2013 | 39,693 |
| 2014 | 39,897 |
| 2015 | 39,797 |
| 2016 | 39,769 |
| 2017 | 39,774 |
| 2018 | 39,760 |
| 2019 | 39,792 |
| 2020 | 40,663 |
| 2021 | 41,078 |
| 2022 | 41,251 |
| 2023 | 41,044 |
| 2024 | 40,981 |
Race & Ethnicity
| White | 94.7% |
| Black or African American | 0.4% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 1.4% |
| Two or More Races | 0.0% |
Age & Sex
49.2
Median Age
49.7%
Female
50.3%
Male
27.1%
Age 65+
Age Distribution
Children (under 15): 13.6% · Seniors (65+): 27.1%
Income & Poverty
| Median household income | $71,903+$130 vs state |
| Mean household income | $95,678 |
| Per-capita income | $42,729 |
| Poverty rate | 4.1%-2.4% vs state |
| Unemployment rate | 2.3% |
| Employment-to-population | 55.6% |
Top Industries by Employment
The largest employment sector in Knox County is professional & business services, accounting for 21.0% of workers.
How residents commute
0.0%
Drive alone
4.7%
Carpool
69.4%
Public transit
14.5%
Work from home
20.1 min
Avg commute
Housing
$290,800+$24,400 vs state
Median home value
$1,079
Median rent
78.5%
Homeownership rate
24,428
Total housing units
73.6%
Occupied
26.4%
Vacant
21.5%
Renter-occupied
Social & access
93.7%
With health insurance
94.4%
With broadband internet
39.6%
Foreign-born
8.6%
Veterans (18+)
12.7%
With a disability
95.6%
Speak language other than English at home
Education
94.3%
High School+
39.1%
Bachelor's+
Largest cities in Maine
Other counties in Maine
Part of Maine
Metro areas in Maine
County rankings
Frequently Asked Questions
Knox County, Maine has a population of 40,860 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 10th-largest county in Maine. Population density is 112 people per square mile.
The population of Knox County has grown 3.2% since 2010 (39,727 → 40,981), a +0.22% annualized rate.
The median household income in Knox County, Maine is $71,903, with mean (average) household income of $95,678 and per-capita income of $42,729. 4.1% of residents live below the federal poverty level.
In Knox County, the largest racial and ethnic groups are White (94.7%), Hispanic or Latino (1.4%), Black or African American (0.4%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Knox County, Maine is 49.2 years. Residents are 49.7% female and 50.3% male.
The median home value in Knox County is $290,800 and median monthly rent is $1,079. 78.5% of occupied housing units are owner-occupied. The county has 24,428 total housing units, 26.4% of which are vacant.
The largest employment sector in Knox County, Maine is professional, scientific, and management services, employing 21.0% of workers. The unemployment rate is 2.3%.
Portland is among the largest cities associated with Knox County, Maine, with a population of 68,505.
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Full rankings of Maine counties
Statewide data for Maine
Population, race, income, age, and trends across Maine
Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.