Allenhurst is a borough located on the Jersey Shore, in Monmouth County, in the U.S. state of New Jersey. The settlement was named after resident Abner Allen and was incorporated as a borough by an act of the New Jersey Legislature on April 26, 1897, from portions of Ocean Township. As of the 2020 United States census, the borough's population was 472…Allenhurst is a borough located on the Jersey Shore, in Monmouth County, in the U.S. state of New Jersey. The settlement was named after resident Abner Allen and was incorporated as a borough by an act of the New Jersey Legislature on April 26, 1897, from portions of Ocean Township. As of the 2020 United States census, the borough's population was 472, a decrease of 24 from the 2010 census count of 496, which in turn reflected a decline of 222 from the 718 counted in the 2000 census.