Moonachie (; ) is a borough in Bergen County, New Jersey, in the Hackensack River watershed. As of the 2010 United States Census, the borough's population was 2,708, reflecting a decline of 46 (-1.7%) from the 2,754 counted in the 2000 Census, which had in turn declined by 63 (-2.2%) from the 2,817 counted in the 1990 Census.