Dayton is an unincorporated community and census-designated place located within South Brunswick, in Middlesex County, New Jersey, United States. At the 2010 United States Census, the CDP's population was 7,063.Dayton has a post office with its own ZIP code that encompasses the entire CDP, as well as some surrounding areas. The community was named after Jonathan Dayton, the youngest person to sign the United States Constitution, who later served as a United States Senator from New Jersey.