Berkeley Heights is a township in Union County, New Jersey, United States, on a ridge in north central New Jersey, Berkeley Heights is a commuter town of New York City, in the Raritan Valley region and also bordering both Morris and Somerset counties in the Passaic Valley region. As of the 2020 United States census the township's population was 13,285, an increase of 102 (+0.8%) from the 2010 census count of 13,183, which in turn reflected a decline of 224 (−1.7%) from the 13,407 counted in the 2000 census.