Mount Ephraim is a Borough in Camden County, New Jersey, United States. As of the United States 2000 Census, the borough population was 4,495. Mount Ephraim was incorporated as a borough by an Act of the New Jersey Legislature on March 23, 1926, from portions of the now-defunct Centre Township. The boroughs of Bellmawr, Runnemede and Lawnside were simultaneously created during the same two-day period.