[22] 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.

On January 15, 2021, Kings Food Market announced they would close their Warren location on Mountain Boulevard.

[1][2] Unincorporated communities, localities and place names located partially or completely within the township include Coontown, Dock Watch Hollow, Gallia, Mount Bethel, Round Top, Smalleytown, Springdale, Union Village,[28] and Warrenville.

[31][32][33] 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.

The 2010 United States census counted 15,311 people, 5,059 households, and 4,285 families in the township.

[48] As of the 2000 United States census[15] there were 14,259 people, 4,629 households, and 3,939 families residing in the township.

[49] Until 2017, the Serbian Orthodox Eparchy of Eastern America was headquartered in Warren Township.

[7][53] At an annual reorganization meeting held in the first week of January, the Township Committee selects one of its members to serve as Mayor.

The historical landmarks they have protected are the Mount Bethel Baptist Meetinghouse, the Kirch–Ford House, and two small family cemeteries.

[61][62][63] For the 119th United States Congress, New Jersey's 7th congressional district is represented by Thomas Kean Jr. (R, Westfield).

[65] For the 2024-2025 session, the 21st legislative district of the New Jersey Legislature is represented in the State Senate by Jon Bramnick (R, Westfield) and in the General Assembly by Michele Matsikoudis (R, New Providence) and Nancy Munoz (R, Summit).

[66] Somerset County is governed by a five-member Board of County Commissioners, whose members are elected at-large to three-year terms of office on a staggered basis, with one or two seats coming up for election each year.

[83] Among the township's 2010 Census population, 68.4% (vs. 60.4% in Somerset County) were registered to vote, including 94.7% of those ages 18 and over (vs. 80.4% countywide).

[94] Schools in the district (with 2020–21 enrollment data from the National Center for Education Statistics.

[101][102][103][104] Students in public school for ninth through twelfth grades attend Watchung Hills Regional High School, which serves students from Warren as well as the neighboring communities of Watchung, Green Brook (in Somerset County) and Long Hill Township (in Morris County).

[107] The district's board of education is comprised of nine members, who are elected directly by the voters to serve three-year terms of office on a staggered basis, with three seats up for each year.

Lakeland Bus Lines provides Route 78 rush-hour service on weekdays from a park and ride at the Warren Corporate Center to Port Authority Bus Terminal in Midtown Manhattan.

[112] Nearby NJ Transit rail service for Warren residents with access to New York Penn Station and Hoboken Terminal is available at the nearby Berkeley Heights, Gillette and Stirling stations.