Hillsborough Township is a township in Somerset County, in the U.S. state of New Jersey. Located in the Raritan Valley region, the township is a suburban and exurban bedroom community of New York City within the New York Metropolitan Area.Capuzzo, Jill P. "Living In Hillsborough, N.J.: A Sprawling Community With an Urban and Rural Feel", The New York Times, January 3, 2018. Accessed August 5, 2023. As of the 2020 United States census, the township's population was 43,276, an increase of 4,973 (+13.0%) from the 2010 census count of 38,303, which in turn reflected an increase of 1,669 (+4.6%) from the 36,634 counted in the 2000 census.Table 7. Population for the Counties and Municipalities in New Jersey: 1990, 2000 and 2010, New Jersey Department of Labor and Workforce Development, February 2011. Accessed May 1, 2023.

Hillsborough Township was originally created by royal charter issued May 31, 1771, which was revoked and revised on September 12, 1771. It was incorporated on February 21, 1798 by the New Jersey Legislature Township Act of 1798 as one of New Jersey's original group of 104 townships. Portions of the township were taken to form the boroughs of Millstone (May 14, 1894) and Manville (April 1, 1929).Snyder, John P. The Story of New Jersey's Civil Boundaries: 1606-1968, Bureau of Geology and Topography; Trenton, New Jersey; 1969. p. 223. Accessed May 28, 2024.New Jersey Local Name Search, State of New Jersey. Accessed February 17, 2014. The township's name may have come from an earlier name of "Hillsbury", though it may have been named for Wills Hill, 1st Marquess of Downshire who was the Earl of Hillsborough.History, Hillsborough Township. Accessed September 15, 2025. "Hillsborough's roads got their names from early records, Hillsborough was also known as Hillsbury and although the records are obscure, some believe the Township was named for Lord Hillsborough.... Hillsborough Township. Accessed December 19, 2019. "Hillsborough received its Charter on May 29, 1771, and officially became Hillsborough Township. Before that date it was known as the 'Westering Precinct of Somerset County'." Based on an analysis of data from the FBI's Uniform Crime Report for 2022, Hillsborough Township was ranked as the second-safest small city in the United States.Martichoux, Alix. "These are the safest small towns and cities in every state: report", The Hill, December 19, 2023. Accessed September 15, 2025.

History On May 31, 1771, Hillsborough was officially granted a Charter incorporating it as a Township. A revised charter was issued on September 12, 1771. The records of Hillsborough Township are complete from their inception in 1746 and there are ten volumes, each some several hundred pages, kept in the Special Collections Department of the Rutgers University Library along with the Charter.

Hillsborough Township quickly took its place in history as the path General George Washington and his troops traveled from the Battle of Princeton to winter quarters in Morristown. While the British were encamped in the valley below awaiting an opportunity to attack, it is said that Washington drilled his troops on the Sourland Mountain around a spring near the top using different formations and corn stalks for guns. As the sun caught the stalks, the British thought Washington had received reinforcements and fresh supplies. The British troops, thinking that they were outnumbered, slipped off to New Brunswick leaving Washington to continue to Morristown.

The township was formally incorporated on February 21, 1798.

Hillsborough is the home of the Belle Mead GSA depot, or Belle Mead General Depot, which was a storage site for materials during World War II, along with housing Italian and German prisoners of war. It continued storing materials until the 1980s, and various contaminants have leaked into the ground and surrounding area during that time. Efforts are under way to convert the site into a mixed recreation and R&D complex.2018 Master Plan Reexamination Report, Hillsborough Township Planning Board, November 29, 2018. Accessed August 5, 2023. "The Belle Mead GSA Depot Redevelopment Plan covers the 369-acre southern half of the former Belle Mead Army Depot. The plan establishes the RD/Research and Development District, which is intended to accommodate a range of low intensity office uses, scientific and applied research facilities, the development and application of technology and production facilities, and recreational uses."

Hillsborough is home to Duke Gardens and Duke Farms, a estate in the north-eastern quadrant of the town that was originally owned by tobacco and electric energy tycoon James "Buck" Duke and then passed down to daughter Doris Duke.Haddon, Heather. "Duke Estate Reopens; Bucolic Grounds Become Public Park, Conservation Center", Wall Street Journal, May 2, 2012. Accessed August 26, 2012. "For years here amid the gentle hills of the Raritan River valley in suburban New Jersey, a 2,740-acre estate that once provided the setting for Doris Duke's ornamental gardens has largely been kept private. Now, after years of debate about how to handle the massive plot formerly owned by one of the world's richest women, the bucolic grounds known as Duke Farms are set to open to the public May 19 and become one of the largest privately owned public spaces in the U.S., estate officials said." As of March 2023, approximately one-third of Hillsborough Township is preserved as Open Space and/or Preserved Farmland.

In Money magazine's 2013 Best Places to Live rankings, Hillsborough was ranked 16th in the nation, the third-highest among the three places in New Jersey included in the top 50 list.Staff. "2013 Best Places to Live; America's best small towns", CNN / Money, September 2013. Accessed August 12, 2013.Staff. 2013 Best Places to Live - 16. Hillsborough, NJ, CNN / Money, September 2013. Accessed August 12, 2013. In the magazine's 2007 rankings, the township was ranked as the 23rd best place to live in the nation.Best Places to Live: Top 100 for 2007 – 23. Hillsborough, N.J.", Money, July 2007. Accessed August 12, 2013.

Geography According to the United States Census Bureau, the township had a total area of 55.10 square miles (142.71 km2), including 54.61 square miles (141.45 km2) of land and 0.49 square miles (1.26 km2) of water (0.88%). Nearly 40% of the land is designated as protected or preserved open space."N.J. town rejects massive warehouse project after nearly 4 years of controversy", NJ Advance News for NJ.com. Accessed September 15, 2025. "Spanning more than 50 square miles, Hillsborough is Somerset County's largest municipality by size. Nearly 40% of its land is preserved as open space."

Unincorporated communities, localities and place names located partially or completely within the township include Amwell, Belle Mead, Blackwells Mills, Champlain, Cloverhill, Clover Mill, Flagtown, Frankfort, Hamilton, Higgins Mills, Hillsborough CDP, Montgomery, Neshanic, Pleasant View, Royce Field, Royce Valley, South Branch, Woods Tavern and Zion.Our Towns , Hillsborough Township. Accessed February 13, 2013. "Hillsborough is a collection of small villages, each of which has left its own imprint on the Townships history: Belle Mead, Blackwells Mills, Flagtown, Neshanic, South Branch"Locality Search, State of New Jersey. Accessed April 27, 2015.

The township borders Branchburg Township, Bridgewater Township, Franklin Township, Manville, Millstone, Montgomery Township, Raritan and Somerville in Somerset County; and East Amwell Township, Raritan Township and Readington Township in Hunterdon County.Areas touching Hillsborough Township, MapIt. Accessed February 24, 2020.Municipalities, Somerset County, New Jersey. Accessed February 24, 2020.New Jersey Municipal Boundaries, New Jersey Department of Transportation. Accessed November 15, 2019.

Ecology According to the A. W. Kuchler U.S. potential natural vegetation types, Hillsborough Township would have an Appalachian Oak (104) vegetation type with an Eastern Hardwood Forest (25) vegetation form.U.S. Potential Natural Vegetation, Original Kuchler Types, v2.0 (Spatially Adjusted to Correct Geometric Distortions), Data Basin. Accessed November 5, 2020.

Climate The township has a humid subtropical climate (Cfa) if the -3 isotherm is used, consistent with most of Somerset County. The low in January, the coldest month on average, is 18 °F (−8 °C), while the high in July, the warmest month on average, is 85 °F (29 °C).

Demographics

2010 census The 2010 United States census counted 38,303 people, 13,573 households, and 10,424 families in the township. The population density was 702.3 per square mile (271.2/km2). There were 14,030 housing units at an average density of 257.3 per square mile (99.3/km2). The racial makeup was 78.61% (30,109) White, 4.59% (1,757) Black or African American, 0.12% (46) Native American, 12.38% (4,743) Asian, 0.04% (15) Pacific Islander, 2.18% (834) from other races, and 2.09% (799) from two or more races. Hispanic or Latino residents of any race were 7.55% (2,893) of the population.

Of the 13,573 households, 40.3% had children under the age of 18; 65.7% were married couples living together; 8.3% had a female householder with no husband present and 23.2% were non-families. Of all households, 19.0% were made up of individuals and 6.3% had someone living alone who was 65 years of age or older. The average household size was 2.81 and the average family size was 3.25.

26.4% of the population was under the age of 18, 6.5% was from 18 to 24, 25.6% from 25 to 44, 32.2% from 45 to 64, and 9.3% was 65 years of age or older. The median age was 39.9 years. For every 100 females, the population had 95.0 males. For every 100 females ages 18 and older there were 91.4 males.

The Census Bureau's 2006–2010 American Community Survey showed that (in 2010 inflation-adjusted dollars) median household income was $105,429 (with a margin of error of +/− $2,892) and the median family income was $119,750 (+/− $2,852). Males had a median income of $81,807 (+/− $5,320) versus $52,366 (+/− $1,804) for females. The per capita income for the borough was $43,029 (+/− $1,701). About 0.8% of families and 1.6% of the population were below the poverty line, including 1.1% of those under age 18 and 4.0% of those age 65 or over.DP03: Selected Economic Characteristics from the 2006-2010 American Community Survey 5-Year Estimates for Hillsborough township, Somerset County, New Jersey , United States Census Bureau. Accessed August 26, 2012.

2000 census

As of the 2000 United States census there were 36,634 people, 12,649 households, and 9,802 families residing in the township. The population density was . There were 12,854 housing units at an average density of . The racial makeup of the township was 85.96% White, 7.31% Asian, 3.76% African American, 0.09% American Indian, 0.06% Pacific Islander, 1.28% from other races, and 1.53% from two or more races. Hispanic or Latino residents of any race were 4.75% of the population.Census 2000 Profiles of Demographic / Social / Economic / Housing Characteristics for Hillsborough township, New Jersey , United States Census Bureau. Accessed August 26, 2012.DP-1: Profile of General Demographic Characteristics: 2000 - Census 2000 Summary File 1 (SF 1) 100-Percent Data for Hillsborough township, Somerset County, New Jersey , United States Census Bureau. Accessed August 26, 2012.

There were 12,649 households, out of which 44.9% had children under the age of 18 living with them . said– 67.6% were married couples living together, 7.5% had a female householder with no husband present, and 22.5% were non-families. 17.8% of all households were made up of individuals, and 4.0% had someone living alone who was 65 years of age or older. The average household size was 2.88, and the average family size was 3.31.