Neptune City is a borough in Monmouth County, in the U.S. state of New Jersey. As of the 2020 United States census, the borough's population was 4,626,
The Borough of Neptune City was incorporated on October 4, 1881, based on a referendum held on March 19, 1881. The boundaries included all of present-day Neptune City, along with what is now Avon-by-the-Sea and the southern portion of Bradley Beach. On March 23, 1900, a bill approved in the New Jersey Legislature created the Borough of Avon-by-the-Sea. On March 13, 1907, the eastern portion of Neptune City was annexed to the Borough of Bradley Beach. The borough was named for Neptune, the Roman water deity, and its location on the Atlantic Ocean.
The earliest borough hall was erected in 1902 at the northwest corner of Evergreen Avenue and Railroad Avenue (now Memorial Drive).
Geography
According to the United States Census Bureau, the borough had a total area of 0.90 square miles (2.32 km<sup>2</sup>), all of which was land.
The borough borders the Monmouth County municipalities of Avon-by-the-Sea, Bradley Beach and Neptune Township.