Berlin is a borough in Camden County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 7,588, reflecting an increase of 1,439 from the 6,149 counted in the 2000 Census, which had in turn increased by 477 from the 5,672 counted in the 1990 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.