North Plainfield is a borough located in Somerset County within the state of New Jersey, United States. It is situated specifically within the Raritan Valley region.
As of the 2020 United States census, the borough had a population of 22,808 residents. This figure represented an increase of 872 people from the 2010 census count of 21,936, which followed a previous increase from 21,103 in the year 2000.