Belleville (French: "Belle ville" meaning "Beautiful city/town") is a township in Essex County, in the U.S. state of New Jersey. As of the 2020 United States census, the township's population was 38,222, an increase of 2,296 (+6.4%) from the 2010 census count of 35,926, which in turn reflected a decline of two people from the 35,928 counted in the 2000 census.
Originally known as "Second River" or "Washington", the inhabitants renamed the settlement "Belleville" in 1797. Belleville was originally incorporated as a township by an act of the New Jersey Legislature on April 8, 1839, from portions of Bloomfield. Portions of the township were taken to create Woodside Township (March 24, 1869, now defunct) and Franklin Township (February 18, 1874, now known as Nutley). The independent municipality of Belleville city was created within the township on March 27, 1874, and was dissolved on February 22, 1876. On November 16, 1910, Belleville was reincorporated as a town, based on the results of a referendum held eight days earlier.
In 1870, Belleville became the first city on the East Coast of the United States with a Chinatown. While much of the country (especially the Western states) had strong anti-Chinese sentiment, the town welcomed a group of Chinese workers from the West Coast who had been workers on building the Central Pacific Railroad. This group of people eventually formed the basis for Chinatowns in Newark and New York City.
In 1981, the town was one of seven Essex County municipalities to pass a referendum to become a township, joining four municipalities that had already made the change, of what would ultimately be more than a dozen Essex County municipalities to reclassify as townships in order take advantage of federal revenue sharing policies that allocated townships a greater share of government aid to municipalities on a per capita basis.
Frankie Valli and the band The Four Seasons formed in Belleville, as did The Delicates, the late-1950s and early-1960s girl group made up of Denise Ferri, Arleen Lanzotti and Peggy Santiglia.