Metuchen ( ) is a borough in Middlesex County, New Jersey, United States, which is northeast of New Brunswick, miles southwest of Newark, southwest of Jersey City, and southwest of Manhattan, all part of the New York metropolitan area. As of the 2010 United States Census, the borough's population was 13,574, reflecting an increase of 734 (+5.7%) from the 12,840 counted in the 2000 Census, which had in turn increased by 36 (+0.3%) from the 12,804 counted in the 1990 Census.