Berlin is a borough in Camden County, in the U.S. state of New Jersey. As of the 2020 United States census, the borough's population was 7,489, a decrease of 99 (−1.3%) from the 2010 census count of 7,588, which in turn reflected an increase of 1,439 (+23.4%) from the 6,149 counted in the 2000 census. Berlin was incorporated as a borough on March 29, 1927, from portions of Berlin Township, based on the results of a referendum held on April 26, 1927.