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.