Bloomfield is a township in Essex County, New Jersey, United States. As of the 2010 United States Census, the township's population was 47,315, reflecting a decline of 368 (-0.8%) from the 47,683 counted in the 2000 Census, which had in turn increased by 2,622 (+5.8%) from the 45,061 counted in the 1990 Census. It surrounds the Bloomfield Green Historic District.