Fairfield Township is a township in Cumberland County, in the U.S. state of New Jersey. It is part of the Vineland-Bridgeton metropolitan statistical area, which encompasses all of Cumberland County for statistical purposes and which constitutes a part of the Delaware Valley. As of the 2020 United States census, the township's population was 5,546,
Fairfield Township was formed by royal charter on May 12, 1697, from portions of the Cohansey Township area, while still part of Salem County, and was formed as a precinct in the newly created Cumberland County on January 19, 1748. It was incorporated on February 21, 1798, as one of the initial group of 104 townships in the state by an act of the New Jersey Legislature. Portions of the township were taken to form Downe Township (September 26, 1772), Millville Township (February 24, 1801) and Lawrence Township (February 17, 1885).
The name Fairfield refers to its original settlers, who were émigrés from Fairfield, Connecticut who settled in the area in 1697. The oldest Presbyterian church in South Jersey is said to date to June 1697. There is a plaque and an old cemetery which indicates the original log building. When it was first created as one of Cumberland County's original six townships, it included land that would later become Commercial Township, Downe Township, Lawrence Township and Millville. and Gouldtown (1,601) are unincorporated communities and census-designated places (CDPs) located within Fairfield Township.
Other unincorporated communities, localities and place names located partially or completely within the township include Back Neck, Ben Davis Point, Clarks Pond, Fordville, Lanings Wharf, Mulfords Landing, New England Crossroads, Sea Breeze and Tindells Landing.
The township has three primary population centers: Sea Breeze, Fairton (originally named Bumbridge) and Gouldtown, an old African American community from the segregation period.
Fairfield Township borders the Cumberland County municipalities of Bridgeton, Deerfield Township, Greenwich Township, Hopewell Township, Lawrence Township, Millville and Upper Deerfield Township, along with the Delaware Bay.