High Quality Content by WIKIPEDIA articles! Medford Lakes is a Borough in Burlington County, New Jersey, United States. As of the 2010 United States Census, the borough population was 4,146, reflecting a decline of 27 (-0.6%) from the 4,173 counted in the 2000 Census, which had in turn declined by 289 (-6.5%) from the 4,462 counted in the 1990 Census.