High Quality Content by WIKIPEDIA articles! Deal is a borough in Monmouth County, New Jersey, United States. As of the 2010 Census, the borough`s population was 750, reflecting a decline of 320 (-29.9%) from the 1,070 counted in the 2000 Census, which had in turn declined by 109 (-9.2%) from the 1,179 counted in the 1990 Census.