Plainsboro Township is a township in Middlesex County in the U.S. state of New Jersey. As of the 2010 United States Census, the township's population was 22,999, reflecting an increase of 2,784 from the 20,215 counted in the 2000 Census, which had in turn increased by 6,002 from the 14,213 counted in the 1990 Census.Plainsboro was incorporated as a township on May 6, 1919, from lands north of Plainsboro Road and Dey Road that had been part of South Brunswick Township and lands south of Plainsboro Road and Dey Road that had been part of Cranbury Township. The main impetus towards the creation of the township was the lack of schools serving the area; a new school was constructed after the township was established, which still exists as J.V.B. Wicoff School, named for one of the individuals who led the effort to create Plainsboro.