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
The poverty rate is what most separates Marathon County from the typical county: 5.4% of residents live below the federal poverty line, against 12.4% nationally. Marathon County is a county in Wisconsin with a population of 138,067. It is the #10-largest of all counties in Wisconsin nationally.
Households take in a median $76,185, comfortably near the US median of $78,538. Only 5.4% of residents live in poverty, below the national 12.4%. Median home value is $205,500, with typical rent around $950.
Educational attainment is on the higher side for US counties — 27.3% of adults hold a four-year degree, below the national 35.0%. About 11.7% of workers primarily work from home, below the national 14.0%, and the average commute runs about 19 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.