Plainfield is a city in Union County, in the U.S. state of New Jersey. Nicknamed "The Queen City", it serves as both a regional hub for Central New Jersey and a bedroom suburb of the New York Metropolitan area, located in the Raritan Valley region. As of the 2020 United States census, the city's population, majority Latino for the first time, was 54,586. This was an increase of 4,778 (+9.6%) from the 2010 census count of 49,808, which in turn reflected an increase of 1,979 (+4.1%) from the 47,829 counted in the 2000 census. In 2023, the Census Bureau estimated the city's population to be 54,670.