Dunellen is a borough in Middlesex County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 7,227, reflecting an increase of 404 (+5.9%) from the 6,823 counted in the 2000 Census, which had in turn increased by 295 (+4.5%) from the 6,528 counted in the 1990 Census.
Dunellen was formed as a borough by an Act of the New Jersey Legislature on October 28, 1887, when it broke away from Piscataway Township, based on the results of a referendum held on March 23, 1886. Dunellen's incorporation was confirmed on April 15, 1914.
Dunellen grew from its start in 1867 with the construction of a railroad station, which was originally called New Market station, serving the nearby community of the same name in Piscataway. When it was originally constructed, the tracks were at grade level with North Avenue and the railroad was the Elizabethtown and Somerville Railroad, which later became part of the Central Railroad of New Jersey. The railroad brought industry to the area.
The Art Color factory built in 1925 was Dunellen's principal industry and produced as many as 10 million magazines a month. The W. F. Hall Printing Company of Chicago bought Art Color in 1931, and ran it until 1968, when it closed the plant there.