Fairfield Township is a township in Cumberland County, New Jersey, United States. It is part of the Vineland-Millville- Bridgeton Primary Metropolitan Statistical Area for statistical purposes. As of the 2010 United States Census, the township's population was 6,295, reflecting an increase of 12 (+0.2%) from the 6,283 counted in the 2000 Census, which had in turn increased by 584 (+10.2%) from the 5,699 counted in the 1990 Census.
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. The oldest Presbyterian church in South Jersey is said to date from before 1697. There is a plaque and an old cemetery which indicates the original log building.