Marathon County, Wisconsin Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 10th-largest in Wisconsin
The population of Marathon County, Wisconsin is 138,067 as of the 2023 American Community Survey, making it the 10th-largest county in Wisconsin. The median household income is $76,185, the median home value is $205,500, and the median age is 41.2.
The population of Marathon County has grown 3.7% since 2010 (134,064 → 139,091), a +0.26% annualized rate.
138,067
Population
+0.26%
Annual growth
89
People / sq mi
$76,185
Median Income
$205,500
Median Home Value
Marathon County covers 1,545 sq mi of land at 89.3 people per square mile.
About Marathon County, WI
Marathon County is a county in Wisconsin with a population of 138,067. It ranks #10 among counties in Wisconsin by population. The median age is 41.2, older than the national median. The population is 50.5% male and 49.5% female.
The median household income in Marathon County is $76,185, near the US median of $74,580. 5.4% of residents live below the federal poverty level. Home values sit at a median of $205,500, with monthly rent averaging $950. The homeownership rate of 73.4% is higher than the national rate of 64.8%.
Educational attainment in Marathon County reflects 27.3% of adults 25 and older holding a bachelor's degree or higher, below the national average of 34.3%. Roughly 11.7% of workers primarily work from home, similar to the national work-from-home rate of 14.2%. The average commute is 19.3 minutes each way.
Marathon County Population History (2010-2024)
The county of Marathon County had a population of 134,064 in 2010 and 139,091 in 2024, a 3.7% growth over 14 years. The peak was 139,091 in 2024. Average annual growth rate: 0.26%.
139,091
Population (2024)
134,064
Population (2010)
139,091
Peak (2024)
0.26%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 134,064 |
| 2011 | 134,355 |
| 2012 | 134,391 |
| 2013 | 134,912 |
| 2014 | 135,173 |
| 2015 | 135,361 |
| 2016 | 135,132 |
| 2017 | 135,525 |
| 2018 | 135,478 |
| 2019 | 135,697 |
| 2020 | 138,114 |
| 2021 | 137,798 |
| 2022 | 138,175 |
| 2023 | 138,838 |
| 2024 | 139,091 |
Race & Ethnicity
| White | 87.9% |
| Black or African American | 0.5% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 1.3% |
| Two or More Races | 0.0% |
Age & Sex
41.2
Median Age
49.5%
Female
50.5%
Male
18.7%
Age 65+
Age Distribution
Children (under 15): 18.5% · Seniors (65+): 18.7%
Income & Poverty
| Median household income | $76,185+$515 vs state |
| Mean household income | $95,540 |
| Per-capita income | $39,970 |
| Poverty rate | 5.4%-1.2% vs state |
| Unemployment rate | 1.9% |
| Employment-to-population | 65.2% |
Top Industries by Employment
The largest employment sector in Marathon County is professional & business services, accounting for 24.2% of workers.
How residents commute
0.3%
Drive alone
1.9%
Carpool
76.5%
Public transit
11.7%
Work from home
19.3 min
Avg commute
Housing
$205,500$-41,900 vs state
Median home value
$950
Median rent
73.4%
Homeownership rate
60,296
Total housing units
94.3%
Occupied
5.7%
Vacant
26.6%
Renter-occupied
Social & access
94.0%
With health insurance
93.3%
With broadband internet
17.0%
Foreign-born
7.1%
Veterans (18+)
12.5%
With a disability
92.5%
Speak language other than English at home
Education
93.1%
High School+
27.3%
Bachelor's+
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County rankings
Frequently Asked Questions
Marathon County, Wisconsin has a population of 138,067 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 10th-largest county in Wisconsin. Population density is 89 people per square mile.
The population of Marathon County has grown 3.7% since 2010 (134,064 → 139,091), a +0.26% annualized rate.
The median household income in Marathon County, Wisconsin is $76,185, with mean (average) household income of $95,540 and per-capita income of $39,970. 5.4% of residents live below the federal poverty level.
In Marathon County, the largest racial and ethnic groups are White (87.9%), Hispanic or Latino (1.3%), Black or African American (0.5%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Marathon County, Wisconsin is 41.2 years. Residents are 49.5% female and 50.5% male.
The median home value in Marathon County is $205,500 and median monthly rent is $950. 73.4% of occupied housing units are owner-occupied. The county has 60,296 total housing units, 5.7% of which are vacant.
The largest employment sector in Marathon County, Wisconsin is professional, scientific, and management services, employing 24.2% of workers. The unemployment rate is 1.9%.
Milwaukee is among the largest cities associated with Marathon County, Wisconsin, with a population of 569,756.
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Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.