Warren Township is a township in Somerset County, in the U.S. state of New Jersey. The township is a bedroom suburb of New York City in the much larger New York metropolitan area, located within the Raritan Valley region. As of the 2020 United States census, the township's population was 15,923, Warren is situated in northeastern Somerset County bordering both Morris (along the Passaic River) and Union counties.
The township has been one of the state's highest-income communities. Based on data from the American Community Survey for 2013–2017, Warren Township residents had a median household income of $154,647, ranked 12th in the state among municipalities with more than 10,000 residents, more than double the statewide median of $76,475.
In 2012, Forbes.com listed Warren as 334th in its listing of "America's Most Expensive ZIP Codes", with a median home price of $842,750.
History
Warren was originally inhabited by the Lenape Native Americans and was colonized in the 1720s by European farmers. As early as 1900, it became a destination for wealthy residents looking to escape nearby New York City. Warren was incorporated as a township by an act of the New Jersey Legislature on March 5, 1806, from portions of Bernards Township and Bridgewater Township. The south-eastern half of the original township (which was close to a railroad and contained most of the population) was separated off as North Plainfield Township (since renamed to Green Brook Township) on April 2, 1872.
Warren was named for Revolutionary War patriot, General Joseph Warren, who was killed at the Battle of Bunker Hill. The township celebrated its 200th anniversary in 2006.
The Historical Sites Committee was formed in 1971 and members are appointed by the governing body to administer municipally owned historic landmarks. The historical landmarks they have protected are the Mount Bethel Baptist Meetinghouse, the Baker–Duderstadt Farm, the Kirch–Ford House, and two small family cemeteries. The Meetinghouse, Baker-Duderstadt Farm, and the Kirch–Ford House are listed on the National Register of Historic Places.
Geography
According to the United States Census Bureau, the township had a total area of 19.64 square miles (50.86 km<sup>2</sup>), including 19.57 square miles (50.68 km<sup>2</sup>) of land and 0.07 square miles (0.18 km<sup>2</sup>) of water (0.36%). and Warrenville.
The township borders Bernards Township to the north and west, Bridgewater Township to the southwest, Green Brook Township to the southeast, and Watchung to the east; all of which lie within Somerset County. Northeastern borders are the communities of Long Hill in Morris County and Berkeley Heights in Union County.
The east–west Second Watchung Mountain ridge bisects Warren, with the northern half of the township sloping northward to the Passaic River and Dead River, and the southern half spanning the Washington Valley, between the First and Second Watchung Mountain ridges, through which runs the East Branch of the Middle Brook. At the border with Bridgewater Township, the Second Watchung Mountain features a prominent cliff face at the now-abandoned Dock Watch Quarry.
As of 2026, the township is a member of Local Leaders for Responsible Planning in order to address the township's Mount Laurel doctrine-based housing obligations.