Monmouth Junction is an unincorporated community and census designated place (CDP)[9] in South Brunswick Township, Middlesex County, New Jersey, United States.[13] Monmouth Junction is in southwestern Middlesex County, in the western part of South Brunswick Township.It is bordered to the northwest by Heathcote, to the northeast by Deans, and to the east by Dayton, all within South Brunswick as well.The 2010 United States census counted 2,887 people, 903 households, and 801 families in the CDP.[13] As of the 2000 United States Census[6] there were 2,721 people, 870 households, and 736 families living in the CDP.[17] People who were born in, residents of, or otherwise closely associated with Monmouth Junction include: