| Official Name: | Fairfield Township, Michigan |
| Settlement Type: | Civil township |
| Pushpin Map: | Michigan#USA |
| Pushpin Label Position: | top |
| Pushpin Label: | Fairfield Township |
| Pushpin Map Caption: | Location within the state of Michigan |
| Mapsize: | 250 |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Michigan |
| Subdivision Type2: | County |
| Subdivision Name2: | Lenawee |
| Leader Title: | Supervisor |
| Leader Name: | Larry Keck |
| Leader Title1: | Clerk |
| Leader Name1: | Debra Keller |
| Unit Pref: | Imperial |
| Area Total Km2: | 108.7 |
| Area Land Km2: | 108.7 |
| Area Water Km2: | 0.0 |
| Area Total Sq Mi: | 42.0 |
| Area Land Sq Mi: | 42.0 |
| Area Water Sq Mi: | 0.0 |
| Population As Of: | 2020 |
| Population Total: | 1661 |
| Population Density Km2: | auto |
| Population Density Sq Mi: | auto |
| Timezone: | Eastern (EST) |
| Utc Offset: | -5 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | -4 |
| Elevation M: | 230 |
| Elevation Ft: | 755 |
| Coordinates: | 41.7781°N -84.0689°W |
| Postal Code Type: | ZIP code(s) |
| Postal Code: | 49221 (Adrian) 49248 (Jasper) 49256 (Morenci) 49279 (Sand Creek) 49289 (Weston) |
| Area Code: | 517 |
| Blank Name: | FIPS code |
| Blank Info: | 26-27020[1] |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 1626263 |
Fairfield Township is a civil township of Lenawee County in the U.S. state of Michigan. As of the 2020 census, the township population was 1,661.[2]
According to the United States Census Bureau, the township has a total area of 42.0 square miles (108.7 km2), all land.
As of the census of 2000, there were 1,756 people, 621 households, and 481 families residing in the township. The population density was 41.8sp=usNaNsp=us. There were 666 housing units at an average density of 15.9sp=usNaNsp=us. The racial makeup of the township was 97.49% White, 0.11% African American, 0.57% Native American, 0.06% Asian, 0.63% from other races, and 1.14% from two or more races. Hispanic or Latino of any race were 3.87% of the population.
There were 621 households, out of which 38.0% had children under the age of 18 living with them, 67.8% were married couples living together, 6.4% had a female householder with no husband present, and 22.4% were non-families. 19.5% of all households were made up of individuals, and 9.2% had someone living alone who was 65 years of age or older. The average household size was 2.81 and the average family size was 3.22.
In the township the population was spread out, with 29.4% under the age of 18, 7.7% from 18 to 24, 27.6% from 25 to 44, 24.3% from 45 to 64, and 11.0% who were 65 years of age or older. The median age was 37 years. For every 100 females, there were 99.8 males. For every 100 females age 18 and over, there were 95.1 males.
The median income for a household in the township was $42,900, and the median income for a family was $47,330. Males had a median income of $35,690 versus $24,259 for females. The per capita income for the township was $17,496. About 2.7% of families and 4.8% of the population were below the poverty line, including 6.0% of those under age 18 and 4.2% of those age 65 or over.