Sparta is a township located in Sussex County within the state of New Jersey in the United States. It serves as a residential and administrative locality within the northern region of the state.
According to the 2020 United States census, the township had a population of 19,600 residents. This figure represented a slight decrease of 122 people from the 2010 count of 19,722, which followed a significant increase of over 1,600 residents from the 2000 census.