| Official Name: | Fairfield Township |
| Settlement Type: | Township |
| Image Map1: | Map of Illinois highlighting Bureau County.svg |
| Mapsize1: | 150px |
| Map Caption1: | Bureau County's location in Illinois |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Illinois |
| Subdivision Type2: | County |
| Subdivision Name2: | Bureau |
| Established Title: | Established |
| Established Date: | November 6, 1849 |
| Area Total Sq Mi: | 36.39 |
| Area Land Sq Mi: | 36.39 |
| Area Water Sq Mi: | 0 |
| Area Water Percent: | 0 |
| Population As Of: | 2020 |
| Population Total: | 379 |
| Population Density Sq Mi: | auto |
| Elevation M: | 191 |
| Elevation Ft: | 627 |
| Coordinates: | 41.5406°N -89.8128°W |
| Timezone: | CST |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Postal Code Type: | ZIP codes |
| Postal Code: | 61283, 61344, 61361 |
| Blank Name: | FIPS code |
| Blank Info: | 17-011-24790 |
| Unit Pref: | Imperial |
Fairfield Township is one of twenty-five townships in Bureau County, Illinois, USA. As of the 2020 census, its population was 379 and it contained 142 housing units.[1]
According to the 2010 census, the township has a total area of, all land.[2]
The township contains three cemeteries:
As of the 2020 census there were 379 people, 114 households, and 106 families residing in the township. The population density was 10.41PD/sqmi. There were 142 housing units at an average density of 3.9/sqmi. The racial makeup of the township was 95.51% White, 0.53% African American, 0.00% Native American, 0.53% Asian, 0.79% Pacific Islander, 0.26% from other races, and 2.37% from two or more races. Hispanic or Latino of any race were 1.06% of the population.
There were 114 households, out of which 45.60% had children under the age of 18 living with them, 82.46% were married couples living together, 10.53% had a female householder with no spouse present, and 7.02% were non-families. 7.00% of all households were made up of individuals, and 7.00% had someone living alone who was 65 years of age or older. The average household size was 4.96 and the average family size was 5.26.
The township's age distribution consisted of 38.5% under the age of 18, 7.2% from 18 to 24, 32.1% from 25 to 44, 15.1% from 45 to 64, and 6.9% who were 65 years of age or older. The median age was 29.2 years. For every 100 females, there were 121.1 males. For every 100 females age 18 and over, there were 66.5 males.
The median income for a household in the township was $78,542, and the median income for a family was $79,375. Males had a median income of $34,531 versus $27,083 for females. The per capita income for the township was $18,520. About 22.6% of families and 33.6% of the population were below the poverty line, including 65.1% of those under age 18 and none of those age 65 or over.