| Official Name: | Flannigan Township |
| Settlement Type: | Township |
| Image Map1: | Map of Illinois highlighting Hamilton County.svg |
| Mapsize1: | 150px |
| Map Caption1: | Hamilton County's location in Illinois |
| Subdivision Type: | Country |
| Subdivision Type1: | State |
| Subdivision Type2: | County |
| Subdivision Name2: | Hamilton |
| Established Title: | Established |
| Established Date: | November 3, 1885 |
| Unit Pref: | Imperial |
| Area Total Sq Mi: | 36.36 |
| Area Land Sq Mi: | 36.20 |
| Area Water Sq Mi: | 0.16 |
| Area Water Percent: | 0.44 |
| Population As Of: | 2020 |
| Population Total: | 291 |
| Population Density Sq Mi: | auto |
| Elevation M: | 168 |
| Elevation Ft: | 551 |
| Coordinates: | 37.9956°N -88.6489°W |
| Timezone: | CST |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Postal Code Type: | ZIP codes |
| Postal Code: | 62859, 62860, 62890 |
| Blank Name: | FIPS code |
| Blank Info: | 17-065-26324 |
Flannigan Township is one of twelve townships in Hamilton County, Illinois, USA. As of the 2020 census, its population was 291 and it contained 166 housing units.
According to the 2021 census gazetteer files, Flannigan Township has a total area of 36.36sqmi, of which 36.2sqmi (or 99.56%) is land and 0.16sqmi (or 0.44%) is water.[1]
(This list is based on USGS data and may include former settlements.)
The township contains these four cemeteries: Cartwright, Little Springs, Knights Prairie and Lampley. Several Revolutionary War veterans are buried at Little Springs. Cartwright cemetery is named after Methodist evangelist and Illinois statesman Peter Cartwright.
As of the 2020 census[2] there were 291 people, 30 households, and 21 families residing in the township. The population density was 8PD/sqmi. There were 166 housing units at an average density of 4.57/sqmi. The racial makeup of the township was 96.91% White, 0.00% African American, 0.34% Native American, 0.34% Asian, 0.00% Pacific Islander, 0.00% from other races, and 2.41% from two or more races. Hispanic or Latino of any race were 0.34% of the population.
There were 30 households, none of which had children under the age of 18 living with them, 70.00% were married couples living together, none had a female householder with no spouse present, and 30.00% were non-families. 30.00% of all households were made up of individuals, and 30.00% had someone living alone who was 65 years of age or older. The average household size was 1.90 and the average family size was 2.29.
The township's age distribution consisted of 0.0% under the age of 18, 0.0% from 18 to 24, 0% from 25 to 44, 36.8% from 45 to 64, and 63.2% who were 65 years of age or older. The median age was 75.8 years. For every 100 females, there were 111.1 males. For every 100 females age 18 and over, there were 111.1 males.
The median income for a household in the township was $54,000. The per capita income for the township was $23,646. No families and 15.8% of the population were below the poverty line, including 25.0% of those age 65 or over.