Belmar is a borough located on the Jersey Shore in Monmouth County, in the U.S. state of New Jersey. As of the 2020 United States census, the borough's population was 5,907, an increase of 113 (+2.0%) from the 2010 census count of 5,794, which in turn reflected a decline of 251 (−4.2%) from the 6,045 counted in the 2000 census.

The Jersey Shore, commonly referred to locally as simply the Shore, is the coastal region of the U.S. state of New Jersey. Geographically, the term encompasses about 141 miles (227 km) of oceanfront bordering the Atlantic Ocean, from Perth Amboy in the north to Cape May Point in the south. The region includes Middlesex, Monmouth, Ocean, Atlantic, and Cape May counties, which are in the central and southern parts of the state. Located in the center of the Northeast Megalopolis, the northern half of the shore region is part of the New York metropolitan area, while the southern half of the shore region is part of the Philadelphia metropolitan area, also known as the Delaware Valley. The Jersey Shore hosts the highest concentration of oceanside boardwalks in the United States.