Haddon Heights 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 7,495, an increase of 22 from the 2010 census count of 7,473, which in turn reflected a decline of 74 from the 7,547 counted in the 2000 census. Haddon Heights was incorporated as a borough by an act of the New Jersey Legislature on March 2, 1904, from portions of the now-defunct Centre Township and parts of Haddon Township.