10th most populous of 72
With 139,091 residents in 2024, Marathon County ranks 10th by population among Wisconsin's 72 counties and is home to 2.3% of the state's residents.

Marathon County has the 7th largest economy in Wisconsin ($11.9 billion GDP) and the 12th largest immigrant share (4.3% foreign-born).
Marathon County is home to 139,091 people (2024 estimate) on 1,545 square miles of land. This page brings together official U.S. Census Bureau population estimates since 2000, the components of change—births, deaths and migration—American Community Survey indicators on income, housing, poverty and education, BEA economic accounts and BLS unemployment.
Pick an indicator to see its long-run evolution.
U.S. Census Bureau: intercensal estimates 2000–2009, Vintage 2020 (2010–2019) and Vintage 2024 (2020–2024), July 1.
| Indicator | Value | Year and source |
|---|---|---|
| Population estimate | 139,091 | 2024 · U.S. Census Bureau |
| Population, 2010 Census | 134,063 | 2010 · U.S. Census Bureau |
| Population, 2000 | 125,995 | July 1, 2000 · Census intercensal |
| Change since 2000 | +10.4% | 2000–2024 · Census |
| International migration | +378 | 2024 · Census Vintage 2024 |
| Domestic migration | −150 | 2024 · Census Vintage 2024 |
| Birth rate | 10.5 per 1,000 | 2024 · calculated |
| Death rate | 10.3 per 1,000 | 2024 · calculated |
| Population rank in Wisconsin | 10th of 72 | 2024 · calculated |
| Per capita personal income | $65,589 | BEA, 2024 · official |
| Gross domestic product | $11.9 billion | BEA, current dollars, 2024 · official |
| Median household income | $77,884 | ACS 2020–2024 5-year · official |
| Poverty rate | 8.7% | ACS 2020–2024 5-year · official |
| Bachelor’s degree or higher | 28.1% | Age 25+, ACS 2020–2024 5-year · official |
| Foreign-born residents | 4.3% | ACS 2020–2024 5-year · official |
| Median home value | $219,600 | ACS 2020–2024 5-year · official |
| Median gross rent | $999/month | ACS 2020–2024 5-year · official |
| Median age | 41.3 years | ACS 2020–2024 5-year · official |
| Households | 57,866 | ACS 2020–2024 5-year · official |
| Owner-occupied homes | 73.3% | ACS 2020–2024 5-year · official |
Comparable indicators for Marathon County, Wisconsin and the United States.
| Indicator | County | Wisconsin | U.S. | Reference |
|---|---|---|---|---|
| Population change 2020–2024 | +0.7% | +1.1% | +2.6% | Census Vintage 2024 |
| Birth rate (per 1,000) | 10.5 | 10.0 | 10.6 | 2024 |
| Death rate (per 1,000) | 10.3 | 9.6 | 9.1 | 2024 |
| Net migration rate (per 1,000) | 1.6 | 4.8 | 8.2 | 2024 |
| Population density (/mi²) | 90.0 | 110.0 | 96.3 | 2024 |
| Per capita personal income | $65,589 | $67,755 | $73,204 | BEA, 2024 |
| Median household income | $77,884 | $77,485 | $80,734 | ACS 2020–2024 5-year |
| Poverty rate | 8.7% | 10.6% | 12.5% | ACS 2020–2024 5-year |
| Bachelor’s degree or higher | 28.1% | 33.4% | 35.7% | Age 25+, ACS 2020–2024 5-year |
| Foreign-born residents | 4.3% | 5.2% | 14.1% | ACS 2020–2024 5-year |
| Median home value | $219,600 | $266,500 | $332,700 | ACS 2020–2024 5-year |
| Median gross rent | $999/month | $1,087/month | $1,413/month | ACS 2020–2024 5-year |
| Median age | 41.3 years | 40.2 years | 38.9 years | ACS 2020–2024 5-year |
| Owner-occupied homes | 73.3% | 67.8% | 65.2% | ACS 2020–2024 5-year |
With 139,091 residents in 2024, Marathon County ranks 10th by population among Wisconsin's 72 counties and is home to 2.3% of the state's residents.
Its population went from 125,995 in 2000 to 139,091 in 2024, a change of +10.4%, compared with +10.9% for Wisconsin as a whole.
In the year to July 2024 the county recorded 1,457 births and 1,434 deaths, so births outnumbered deaths by 23.
Annual Census estimates since 2000 put the county's highest population in 2024, at 139,091.
Marathon County has about 90.0 residents per square mile of land, ranking 23rd of 72 counties; Wisconsin averages 110.0.
With a median household income of $77,884 (ACS 2020–2024 5-year), the county ranks 19th of 72 Wisconsin counties; the state median is $77,485.
Its economy produced $11.9 billion of GDP in 2024 (BEA), 7th largest among 72 Wisconsin counties.
Real GDP grew 2.5% in 2024, adjusted for inflation (BEA, chained 2017 dollars).