| Official Name: | Guenther, Wisconsin |
| Settlement Type: | Town |
| Mapsize: | 250px |
| Subdivision Type: | Country |
| Subdivision Name: |  United States |
| Subdivision Type1: | State |
| Subdivision Type2: | County |
| Subdivision Name2: | Marathon |
| Unit Pref: | Imperial |
| Area Total Km2: | 89.9 |
| Area Land Km2: | 89.8 |
| Area Water Km2: | 0.1 |
| Population As Of: | 2010 |
| Population Total: | 341 |
| Population Density Km2: | auto |
| Timezone: | Central (CST) |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Elevation Footnotes: | [1] |
| Elevation M: | 355 |
| Elevation Ft: | 1165 |
| Coordinates: | 44.7275°N -89.5569°W |
| Blank Name: | FIPS code |
| Blank Info: | 55-31800[2] |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 1583330 |
Guenther is a town in Marathon County, Wisconsin, United States. It is part of the Wausau, Wisconsin Metropolitan Statistical Area. The population was 341 at the 2010 census.[3] The unincorporated communities of Ashley and Rocky Corners are located partially in the town.
According to the United States Census Bureau, the town has a total area of 89.9sqkm, of which 89.8sqkm is land and 0.1sqkm, or 0.12%, is water.[4]
At the 2000 census there were 302 people, 114 households, and 82 families living in the town. The population density was 8.8 people per square mile (3.4/km). There were 130 housing units at an average density of 3.8 per square mile (1.5/km). The racial makeup of the town was 99.01% White, 0.33% African American and 0.66% Native American. Hispanic or Latino of any race were 0.33%.
Of the 114 households 30.7% had children under the age of 18 living with them, 62.3% were married couples living together, 4.4% had a female householder with no husband present, and 27.2% were non-families. 17.5% of households were one person and 5.3% were one person aged 65 or older. The average household size was 2.65 and the average family size was 3.13.
The age distribution was 23.8% under the age of 18, 4.6% from 18 to 24, 35.1% from 25 to 44, 23.5% from 45 to 64, and 12.9% 65 or older. The median age was 38 years. For every 100 females, there were 125.4 males. For every 100 females age 18 and over, there were 134.7 males.
The median household income was $43,250 and the median family income was $48,750. Males had a median income of $31,667 versus $25,625 for females. The per capita income for the town was $18,475. About 2.6% of families and 5.5% of the population were below the poverty line, including none of those under the age of eighteen and 16.7% of those sixty five or over.