Somerdale is a borough in Camden County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 5,151, reflecting a decline of 41 from the 5,192 counted in the 2000 Census, which had in turn declined by 248 from the 5,440 counted in the 1990 Census.The Borough of Somerdale was created on April 23, 1929, from Clementon Township, one of seven municipalities created from the now-defunct township, and one of five new municipalities created on that same date.