Belleville is a township located in Essex County within the state of New Jersey in the United States. It serves as a residential and community hub within the northern region of the state.
According to the 2020 United States census, the township had a population of 38,222 residents. This figure represents an increase of 2,296 people, or approximately 6.4%, compared to the 35,926 residents recorded in the 2010 census.