Long Branch is a beachside city in Monmouth County, New Jersey, United States. As of the 2010 United States Census, the city's population was 30,719, reflecting a decline of 621 from the 31,340 counted in the 2000 Census, which had in turn increased by 2,682 from the 28,658 counted in the 1990 Census.Long Branch was formed on April 11, 1867, as the Long Branch Commission, from portions of Ocean Township. Long Branch was incorporated as a city by an act of the New Jersey Legislature on April 8, 1903, based on the results of a referendum, replacing the Long Branch Commission.