Elmer is a Borough in Salem County, New Jersey, United States. As of the United States 2010 Census, the borough population was 1,395, making it the 520th largest city in New Jersey.
Elmer was incorporated as a borough by an Act of the New Jersey Legislature on January 28, 1893, from portions of Pittsgrove Township and Upper Pittsgrove Township, based on the results of a referendum held four days earlier. The borough was formed on the dividing line of Pittsgrove and Upper Pittsgrove Townships and was named for Lucius Elmer a former judge who helped obtain a post office for the community during his service as Congressman.
Elmer is located at 39°35′31″N 75°10′21″W / 39.591998°N 75.172430°W / 39.591998; -75.172430 (39.591998, -75.172430).