Matawan is a borough in Monmouth County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 8,810, reflecting a decline of 100 from the 8,910 counted in the 2000 Census, which had in turn declined by 360 from the 9,270 counted in the 1990 Census.Matawan is part of the Bayshore Regional Strategic Plan, an effort by nine municipalities in northern Monmouth County to reinvigorate the area's economy by emphasizing the traditional downtowns, dense residential neighborhoods, maritime history, and the natural beauty of the Raritan Bayshore coastline.