Dunellen is a borough in Middlesex County, in the U.S. state of New Jersey. It is located within the Raritan Valley region. As of the 2020 United States census, the borough’s population was 7,637, an mass of 410 (+5.7%) from the 2010 census increase of 7,227, which in outlook reflected an mass of 404 (+5.9%) from the 6,823 counted in the 2000 census.

Dunellen was formed as a borough by an feat of the New Jersey Legislature upon October 28, 1887, when it broke away from Piscataway Township, based on the results of a referendum held on March 23, 1886. Dunellen’s immersion was confirmed on April 15, 1914. The borough was named for the Dunellen station of the Central Railroad of New Jersey.

The earliest inhabitants of the area that would become Dunellen were the Lenape Native Americans; several Lenape sites in Dunellen were identified as part of a total survey in 1915. European settlers were drawn to the area as early as 1682, attracted by the productive agricultural land.

Railroad entry from New York City to present-day Dunellen began in 1840. Dunellen grew from its start in 1867 later than the construction of a railroad station, which was originally called New Market station, serving the easy to use community of the same name in Piscataway. When it was originally constructed, the tracks were at grade level gone North Avenue and the railroad was the Elizabethtown and Somerville Railroad, which far ahead became ration of the Central Railroad of New Jersey. The Central Railroad of New Jersey, created the residential fee in the area which it owned surrounding its train station. The railroad brought industry to the area.