| Official Name: | Marrs Township Posey County |
| Settlement Type: | Township |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Indiana |
| Subdivision Type2: | County |
| Subdivision Name2: | Posey |
| Government Type: | Indiana township |
| Area Total Km2: | 134.98 |
| Area Land Km2: | 133.5 |
| Area Water Km2: | 1.48 |
| Area Total Sq Mi: | 52.12 |
| Area Land Sq Mi: | 51.54 |
| Area Water Sq Mi: | 0.57 |
| Population As Of: | 2020 |
| Population Total: | 5,385 |
| Population Density Km2: | 36.47 |
| Population Density Sq Mi: | 94.44 |
| Elevation Footnotes: | [1] |
| Elevation M: | 133 |
| Elevation Ft: | 436 |
| Coordinates: | 37.9464°N -87.7558°W |
| Blank Name: | FIPS code |
| Blank Info: | 18-47250[2] |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 453614 |
Marrs Township is one of ten townships in Posey County, Indiana. At the 2000 census, its population was 4,868. By the 2020 census it had risen to 5,385.[3]
Marrs Township was organized in 1817.[4] The township was named for Samuel R. Marrs, a pioneer settler and afterward county commissioner.[5]
At the 2020 census there were 5,385 people, 2,094 housing units and 1,949 households residing in the township. The population density was 104.6 inhabitants per square mile. The racial makeup was 94% White, 1% African American, 0% Native American, 1% Asian, 0% Pacific Islander, 2% from other races, and 2% from two or more races. Hispanic or Latino of any race was 0% of the population.
Of the family households, 76% were married couples, 5% were a male householder with no spouse, and 5% were a female householder with no spouse. The average household had 2.8 people.
The median age was 40.1, 26% of people were under the age of 18, and 18% were 65 years of age or older. Of the residents none spoke a language other than English at home, and 1.3% were born outside the United States, 13% in Europe and 87% in Asia.
The median income for a household in the township was $119,933. 5.9% of the population were military veterans, and 34.2% had a batchelors degree or higher. In the CDP 9.9% of the population was below the poverty line, including 10% of those under age 18 and 12% of those age 65 or over.
It is within the Metropolitan School District of Mt. Vernon,[6] which operates Mount Vernon High School.