Central Jersey
Central Jersey, or Central New Jersey, is the middle region of the U.S. state of New Jersey. The designation Central Jersey is a distinct administrative toponym. While New Jersey is often divided into North Jersey and South Jersey, many residents recognize Central Jersey as a distinct third entity. As of the 2020 census, Central Jersey has a population of 3,580,999.
All descriptions of Central Jersey include Middlesex County, the population center of New Jersey, and most include much of nearby Monmouth, Mercer, Somerset, and Hunterdon counties. The inclusion of adjacent Union and Ocean counties on the north and south of the region, respectively, is a source of debate. In 2015, New Jersey Business magazine defined Central Jersey more narrowly as the five counties of Hunterdon, Mercer, Middlesex, Monmouth, and Somerset.
In 2022, legislation was proposed in the New Jersey Legislature to establish distinct geographic areas for tourism in the state. Bill A4711 was sponsored by Assemblymembers Roy Freiman, Sadaf Jaffer, and Anthony Verrelli in the New Jersey General Assembly. This included an official designation of the region of Central Jersey, which the legislation defines more broadly as the seven counties of Hunterdon, Mercer, Middlesex, Monmouth, Ocean, Somerset, and Union. The New Jersey Senate version of this legislation passed by a vote of 36-1 on June 20, 2023. On August 24, 2023, Gov. Murphy signed legislation officially designating Central Jersey including, at a minimum, the counties of Hunterdon, Mercer, Middlesex, and Somerset.
Trenton, the seat of Mercer County and the state capital of New Jersey, is located in Central Jersey. New Jersey's geographic center is in Hamilton, Mercer County. In 2011, the population center of the state was in the western portion of East Brunswick, in Middlesex County. The two busiest highways in New Jersey, the New Jersey Turnpike and the Garden State Parkway, intersect in Woodbridge, Middlesex County. Princeton University and Rutgers University, the two most prominent institutions of higher education in the state, are situated in Central Jersey, partially contributing to the region's status as the world's largest pharmaceutical industry hub.
Geography
The region lies roughly at the geographic heart of the Northeast megalopolis and is wholly in the New York metropolitan area, the nation's largest metropolitan area. All of Central Jersey has a hot-summer humid continental climate.The Delaware Valley is another area that is associated with some parts of Central Jersey, specifically Mercer County. Yet despite the County’s close geographic proximity to Philadelphia's combined statistical area, Mercer County is considered part of the New York Combined Metropolitan Statistical Area as defined by the United States Census Bureau. Some but not all regions of Hunterdon County associate themselves with the Delaware Valley and the Philadelphia metropolitan area.
The Raritan Valley is the region along the middle reaches of the Raritan River and its North Branch and South Branch. The Raritan Valley includes the communities of Branchburg, Bridgewater, Somerville, Raritan, Hillsborough, Franklin Township, Green Brook, North Plainfield, Bound Brook, and South Bound Brook, all in Somerset County; Dunellen, Middlesex, Piscataway, South Plainfield, Highland Park, New Brunswick, East Brunswick, Edison, and Metuchen, all in the northern and central portions of Middlesex County; and Plainfield in southwestern Union County.
The Raritan Bayshore is used to describe the region in Middlesex and Monmouth Counties, located along the coastline of the Raritan Bay, from the mouth of the Raritan River in the west to the barrier island of Sandy Hook bordering the Atlantic Ocean in the east. The Raritan Bayshore includes the communities of Sayreville, Woodbridge, Perth Amboy, South Amboy, and Old Bridge, all in northeastern Middlesex County; Aberdeen, Matawan, Keyport, Union Beach, Hazlet, Keansburg, Holmdel, Middletown, Atlantic Highlands, and Highlands, all in northern Monmouth County.
The telephone area codes 732 and 848 includes Middlesex, Monmouth, Somerset, Union, and northern Ocean counties. While area codes 609 and 640 includes southern Ocean, Hunterdon, and Somerset counties, as well as Mercer County.
Colonial era
Between 1674 and 1702, in the early part of New Jersey's colonial period, the border between West Jersey and East Jersey ran diagonally across the middle part of the state. The Keith Line, as the demarcation is known, ran through the center of what is now Mercer County. This border remained important in determining ownership and political boundaries until 1745. Remnants of that division are seen today, notably as the Hunterdon-Somerset, Ocean-Burlington, and Monmouth-Burlington county lines. The division of the two provinces was cultural as well as geographical.New Jersey's position between the cities of New York and Philadelphia led to the saying that the state was like "a barrel tapped at both ends", a quote often attributed to Benjamin Franklin. Travel between the two cities originally included a ferry crossing. Due to the obstacles created by the Meadowlands and the Hudson Palisades, passengers from New York would cross the North River and the Upper New York Bay by boat and then transfer to stagecoaches to travel overland through what is now Central Jersey. One route from Elizabethtown to Lambertville was known as Old York Road. Another route, from Perth Amboy through Kingston to Burlington, ran along a portion of the Kings Highway, These roads followed Lenape paths known respectively as the Naritcong Trail and the Assunpink Trail.
Raritan Landing, across from New Brunswick in today's Piscataway, became an important inland port and commercial hub for the region. Two of the nine Colonial Colleges, founded before the American Revolution, were the College of New Jersey, and Queens College.
Population
| Rank | County | Population | County Seat | Area |
| 1 | Middlesex | 829,685 | New Brunswick | 311 sq mi |
| 2 | Monmouth | 621,354 | Freehold Borough | 472 sq mi |
| 3 | Mercer | 369,811 | Trenton | 226 sq mi |
| 4 | Somerset | 331,164 | Somerville | 305 sq mi |
| 5 | Hunterdon | 124,714 | Flemington | 430 sq mi |
Asian American population
Asian Indian population
Central New Jersey, particularly Edison and surrounding Middlesex County, is prominently known for its significant concentration of Asian Indians. The world's largest Hindu temple outside Asia was inaugurated in Robbinsville in 2014, a BAPS temple. The growing Little India is a South Asian-focused commercial strip in Middlesex County, the U.S. county with the highest concentration of Asian Indians, at nearly 20% as of 2020. The Oak Tree Road strip runs for about one-and-a-half miles through Edison and neighboring Iselin in Woodbridge Township, near the area's sprawling Chinatown and Koreatown, running along New Jersey Route 27. It is the largest and most diverse South Asian cultural hub in the United States. Monroe Township, in Middlesex County, has experienced a particularly rapid growth rate in its Indian American population, with an estimated 5,943 as of 2017, which was 23 times the 256 counted as of the 2000 Census; and Diwali is celebrated by the township as a Hindu holiday. Carteret's Punjabi Sikh community, variously estimated at upwards of 3,000, constitutes the largest concentration of Sikhs in the state. In Middlesex County, election ballots are printed in English, Spanish, Gujarati, Hindi, and Punjabi.Indian pharmaceutical and technology companies are coming to Central New Jersey to gain a foothold in the United States. Dr. Reddy's Laboratories, based in Hyderabad, set up its U.S. headquarters in Princeton, Mercer County. Pharmaceutical company Aurobindo, also headquartered in Hyderabad, has established its U.S. headquarters in East Windsor, Mercer County, and has implemented a multimillion-dollar expansion of these Central New Jersey operations. In March 2023, Bengaluru-based technology services and consulting company Wipro opened its American international headquarters in East Brunswick, Middlesex, County. In July 2025, Biocon Biologics established its U.S. headquarters in Bridgewater, Somerset County.
Chinese population
Starting in the 2000s, highly educated suburbs in central and northern New Jersey have received a large influx of Chinese immigrants, including many Taiwanese immigrants. Many Chinese American families send their children to Mandarin language schools in Edison. Some of these private schools include Edison Chinese School, located at John Adams Middle School, or Tzu Chi, located at Woodrow Wilson Middle School, both of which teach in Traditional Chinese, in addition to Huaxia Chinese School, which teaches in Simplified Chinese.The Taiwanese airline China Airlines provides private bus service to John F. Kennedy International Airport from the Kam Man Food location in Edison to feed its flight to Taipei, Taiwan.