Fairfield Township may refer to:
Illinois
- Fairfield Township, Bureau County, Illinois
Indiana
- Fairfield Township, DeKalb County, Indiana
- Fairfield Township, Franklin County, Indiana
- Fairfield Township, Tippecanoe County, Indiana
Iowa
- Fairfield Township, Buena Vista County, Iowa
- Fairfield Township, Cedar County, Iowa
- Fairfield Township, Fayette County, Iowa
- Fairfield Township, Grundy County, Iowa
- Fairfield Township, Jackson County, Iowa
- Fairfield Township, Palo Alto County, Iowa
Kansas
- Fairfield Township, Russell County, Kansas
Michigan
- Fairfield Township, Lenawee County, Michigan
- Fairfield Township, Shiawassee County, Michigan
Minnesota
- Fairfield Township, Crow Wing County, Minnesota
- Fairfield Township, Swift County, Minnesota
Missouri
- Fairfield Township, Carroll County, Missouri
Nebraska
- Fairfield Township, Clay County, Nebraska
- Fairfield Township, Harlan County, Nebraska
New Jersey
- Fairfield Township, Cumberland County, New Jersey
- Fairfield Township, Essex County, New Jersey
North Carolina
- Fairfield Township, Hyde County, North Carolina, in Hyde County, North Carolina
North Dakota
- Fairfield Township, Grand Forks County, North Dakota, in Grand Forks County, North Dakota
Ohio
- Fairfield Township, Butler County, Ohio
- Fairfield Township, Columbiana County, Ohio
- Fairfield Township, Highland County, Ohio
- Fairfield Township, Huron County, Ohio
- Fairfield Township, Madison County, Ohio
- Fairfield Township, Tuscarawas County, Ohio
- Fairfield Township, Washington County, Ohio
Pennsylvania
- Fairfield Township, Crawford County, Pennsylvania
- Fairfield Township, Lycoming County, Pennsylvania
- Fairfield Township, Westmoreland County, Pennsylvania
South Dakota
- Fairfield Township, Beadle County, South Dakota, in Beadle County, South Dakota