Ewing Township is a township in Mercer County, New Jersey, United States. The township is within the New York metropolitan area as defined by the United States Census Bureau. It also directly borders the Philadelphia metropolitan area and is part of the Federal Communications Commission's Philadelphia Designated Market Area. As of the 2010 United States Census, the township's population was 35,790, reflecting an increase of 83 (+0.2%) from the 35,707 counted in the 2000 Census, which had increased by 1,522 (+4.5%) from the 34,185 counted in the 1990 Census.