| Official Name: | Mendon Township |
| Settlement Type: | Township |
| Image Map1: | Map of Illinois highlighting Adams County.svg |
| Mapsize1: | 150px |
| Map Caption1: | Adams County's location in Illinois |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Illinois |
| Subdivision Type2: | County |
| Subdivision Name2: | Adams |
| Established Title: | Established |
| Established Date: | November 6, 1849 |
| Area Total Sq Mi: | 36.76 |
| Area Land Sq Mi: | 36.65 |
| Area Water Sq Mi: | 0.11 |
| Area Water Percent: | 0.30 |
| Population As Of: | 2020 |
| Population Total: | 1445 |
| Population Density Sq Mi: | auto |
| Elevation M: | 222 |
| Elevation Ft: | 728 |
| Coordinates: | 40.0886°N -91.2947°W |
| Timezone: | CST |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Postal Code Type: | ZIP codes |
| Postal Code: | 62301, 62338, 62349, 62351, 62376 |
| Blank Name: | FIPS code |
| Blank Info: | 17-001-48320 |
| Unit Pref: | Imperial |
Mendon Township is one of twenty-two townships in Adams County, Illinois, United States. As of the 2020 census, its population was 1,445 and it contained 600 housing units.[1]
The township is named after Mendon, Massachusetts.[2]
According to the 2010 census, the township has a total area of, of which (or 99.70%) is land and (or 0.30%) is water.[3]
The township contains three cemeteries: Franklin, Moyer and Saint Joseph.
As of the 2020 census there were 1,445 people, 603 households, and 453 families residing in the township. The population density was 39.26PD/sqmi. There were 600 housing units at an average density of 16.3/mi2. The racial makeup of the township was 95.22% White, 0.48% African American, 0.00% Native American, 0.00% Asian, 0.00% Pacific Islander, 0.62% from other races, and 3.67% from two or more races. Hispanic or Latino of any race were 1.11% of the population.
There were 603 households, out of which 43.10% had children under the age of 18 living with them, 62.85% were married couples living together, 8.46% had a female householder with no spouse present, and 24.88% were non-families. 24.20% of all households were made up of individuals, and 17.10% had someone living alone who was 65 years of age or older. The average household size was 2.74 and the average family size was 3.25.
The township's age distribution consisted of 30.4% under the age of 18, 6.1% from 18 to 24, 22.8% from 25 to 44, 23.2% from 45 to 64, and 17.4% who were 65 years of age or older. The median age was 38.5 years. For every 100 females, there were 99.6 males. For every 100 females age 18 and over, there were 86.9 males.
The median income for a household in the township was $68,854, and the median income for a family was $86,125. Males had a median income of $41,979 versus $37,750 for females. The per capita income for the township was $29,633. About 4.9% of families and 6.4% of the population were below the poverty line, including 8.7% of those under age 18 and 7.8% of those age 65 or over.