Newton is a town in Sussex County, New Jersey, United States. As of the United States 2000 Census, the town population was 8,244. It is the county seat of Sussex County. Newton was incorporated by an Act of the New Jersey Legislature on April 11, 1864 from portions of Newton Township, which was also partitioned to create Andover Township and Hampton Township, and was then dissolved. Additional land was acquired from Andover Township in 1869 and 1927, and from Fredon Township in 1920.