The land comprising what is now Jersey City was inhabited by the Lenape, a collection of tribes (later called Delaware Indian). In 1609, Henry Hudson, seeking an alternate route to East Asia, anchored his small vessel Halve Maen (English: Half Moon) at Sandy Hook, Harsimus Cove and Weehawken Cove, and elsewhere along what was later named the North River. After spending nine days surveying the area and meeting its inhabitants, he sailed as far north as Albany. The contemporary flag of the city is a variation on the Prince's Flag from the Netherlands. The stripes are blue, white and yellow, with the center of the flag showing the city seal, depicting Hudson's ship, the Half Moon, and other modern vessels.

By 1621, the Dutch West India Company was organized to manage this new territory and in June 1623, New Netherland became a Dutch province, with headquarters in New Amsterdam. Michael Reyniersz Pauw received a land grant as patroon on the condition that he would establish a settlement of not fewer than fifty persons within four years. He chose the west bank of the North River (Hudson River) and purchased the land from the Lenape. This grant is dated November 22, 1630, and is the earliest known conveyance for what are now Hoboken and Jersey City. Pauw, however, was an absentee landlord who neglected to populate the area and was obliged to sell his holdings back to the Company in 1633. That year, a house was built at Communipaw for Jan Evertsen Bout, superintendent of the colony, which had been named Pavonia (the Latinized form of Pauw's name, which means "peacock"). Shortly after, another house was built at Harsimus Cove and became the home of Cornelius Van Vorst, who had succeeded Bout as superintendent, and whose family would become influential in the development of the city. Relations with the Lenape deteriorated, in part because of the colonialist's mismanagement and misunderstanding of the indigenous people, and led to series of raids and reprisals and the virtual destruction of the settlement on the west bank. During Kieft's War, approximately eighty Lenapes were killed by the Dutch in a massacre at Pavonia on the night of February 25, 1643.

Scattered communities of farmsteads characterized the Dutch settlements at Pavonia: Communipaw, Harsimus, Paulus Hook, Hoebuck, Awiehaken, Pamrapo, and other lands "behind Kill van Kull". The village of Bergen (located inside a palisaded garrison) was established on what is now Bergen Square in 1660 and officially chartered on September 5, 1661 as the state's first local civil government. As a result, it is regarded as the first permanent settlement and oldest municipality in what would become the state of New Jersey. In addition, the oldest surviving houses in Jersey City are of Dutch origin including the Newkirk House (1690), the Van Vorst Farmhouse (1740), and the Van Wagenen House (1742).

During the American Revolutionary War, the area was in the hands of the British who controlled New York. In the Battle of Paulus Hook, Major Light Horse Harry Lee successfully attacked a British fortification on August 19, 1779, which was the catalyst for the British losing control of what is now modern New Jersey. The battle itself took place within what is present-day Jersey City.

In 1804, Alexander Hamilton, now a private citizen, was focused on increasing manufacturing in the greater New York City area. To that end, he helped to create the Associates of the Jersey Company which would lay the groundwork for modern Jersey City through private development. The consortium behind the company were predominantly Federalists who, like Hamilton, had been swept out of power in the election of 1800 by Thomas Jefferson and other Democratic-Republicans. Large tracts of land in Paulus Hook were purchased by the company with the titles owned by Anthony Dey, who was from a prominent old Dutch family, and his two cousins, Colonel Richard Varick, the former mayor of New York City (1789 - 1801), and Jacob Radcliff, a Justice of the New York Supreme Court who would later become mayor of New York City (twice) from 1810 to 1811 and again from 1815 - 1818. They laid out the city squares and streets that still characterize the neighborhood, giving them names also seen in Lower Manhattan or after war heroes (Grove, Varick, Mercer, Wayne, Monmouth and Montgomery among them).

Despite Hamilton's untimely death in August 1804, the Association carried on, though the enterprise was mired in a legal dispute between New York City and the state of New Jersey over who owned the waterfront. The unresolved dispute would continue until the Treaty of 1834 where New York City formally ceded control of Jersey City to New Jersey. Over that time though, the Jersey Company applied to the New Jersey Legislature to incorporate the Town of Jersey. The legislature enacted "An Act to incorporate the City of Jersey, in the County of Bergen" on January 28, 1820. Under the provision, five freeholders (including Varick, Dey, and Radcliff) were to be chosen as "the Board of Selectmen of Jersey City," thereby establishing the first governing body of the emerging municipality. The city was reincorporated on January 23, 1829, and again on February 22, 1838, at which time it became completely independent of North Bergen and was given its present name. On February 22, 1840, it became part of the newly created Hudson County.

During the 19th century, former slaves reached Jersey City on one of the four routes of the Underground Railroad that led to the city.

Soon after the Civil War, the idea arose of uniting all of the towns of Hudson County east of the Hackensack River into one municipality. A bill was approved by the state legislature on April 2, 1869, with a special election to be held on October 5, 1869. An element of the bill provide that only contiguous towns could be consolidated. While a majority of the voters across the county approved the merger, the only municipalities that had approved the consolidation plan and that adjoined Jersey City were Hudson City and Bergen City. The consolidation began on March 17, 1870, taking effect on May 3, 1870. Three years later the present outline of Jersey City was completed when Greenville agreed to merge into the Greater Jersey City.

In the late 1880s, three passenger railroad terminals opened in Jersey City next to the Hudson River (Pavonia Terminal,Exchange Place and Communipaw). Tens of millions of immigrants passed through these stations as they made their way westward from Ellis Island into the United States. The railroads transformed the geography of the city by building the Erie Cut as well as several large freight rail yards. The railroads became and would remain the largest employers in Jersey City into and during the early 20th century.

Jersey City was a dock and manufacturing town for much of the 19th and 20th centuries. Much like New York City, Jersey City has always been a destination for new immigrants to the United States. In its heyday before World War II, German, Irish, and Italian immigrants found work at Colgate, Chloro or Dixon Ticonderoga. In 1908, the first permanent disinfection system for drinking water in the U.S. was installed on the water supply for the city by John L. Leal. The Hudson Tubes opened in 1911, allowing passengers to take the train to Manhattan as an alternative to the extensive ferry system. The Black Tom explosion occurred on July 30, 1916, as an act of sabotage on American ammunition supplies by German agents to prevent the materials from being used by the Allies in World War I.

From 1917 to 1947, Jersey City was governed by Mayor Frank Hague. Originally elected as a candidate supporting reform in governance, the Jersey City History website says his name is "synonymous with the early twentieth century urban American blend of political favoritism and social welfare known as bossism". Hague ran the city with an iron fist while, at the same time, molding governors, United States senators, and judges to his whims. Boss Hague was known to be loud and vulgar, but dressed in a stylish manner, earning him the nickname "King Hanky-Panky". In his later years in office, Hague would often dismiss his enemies as "reds" or "commies". Hague lived like a millionaire, despite having an annual salary that never exceeded $8,500. He was able to maintain a fourteen-room duplex apartment in Jersey City, a suite at the Plaza Hotel in Manhattan, and a palatial summer home in the seaside community of Deal, and travel to Europe yearly in the royal suites of the best ocean liners.

After Hague's retirement from politics, a series of mayors including John V. Kenny, Thomas J. Whelan and Thomas F. X. Smith attempted to take control of Hague's organization, usually under the mantle of political reform. None were able to duplicate the level of power held by Hague, but the city and the county remained notorious for political corruption for years. By the 1970s the city experienced a period of urban decline that saw many of its wealthy residents leave for the suburbs, due to rising crime, civil unrest, political corruption, and economic hardship. From 1950 to 1980, Jersey City lost 75,000 residents, and from 1975 to 1982, it lost 5,000 jobs, or 9% of its workforce.

Beginning in the 1980s, development of the waterfront in an area previously occupied by rail yards and factories helped to stir the beginnings of a renaissance for Jersey City. The rapid construction of numerous high-rise buildings increased the population and led to the development of the Exchange Place financial district, also known as "Wall Street West", one of the largest financial centers in the United States. Large financial institutions such as UBS, Goldman Sachs, Chase Bank, Citibank, and Merrill Lynch occupy prominent buildings on the Jersey City waterfront, some of which are among the tallest buildings in New Jersey. Simultaneous to this building boom, the light-rail network was developed. With 18,000,000 square feet (1,700,000 m²) of office space as of 2011, it has the nation's 12th-largest downtown.

City Ordinance 13.097, passed in October 2013, requires employers with ten or more employees to offer up to five paid sick days a year. The bill impacts all businesses employing workers who work at least 80 hours a calendar year in Jersey City.

At the 2019 census estimate, Jersey City had a population of 262,075, up from 247,597 at the 2010 United States Census. The population density was 17,954.6 persons per square mile. At the 2010 Census, Jersey City experienced an increase of 7,542 residents (3.1%) from its 2000 Census population of 240,055. Since it was believed the earlier population was under-counted, the 2010 Census was anticipated with the possibility that Jersey City might become the state's most populated city, surpassing Newark. The city hired an outside firm to contest the results, citing the fact that development in the city between 2000 and 2010 substantially increased the number of housing units and that new populations may have been under-counted by as many as 30,000 residents based on the city's calculations. Preliminary findings indicated that 19,000 housing units went uncounted.

Per the American Community Survey's 2014-2018 estimates, Jersey City's age distribution was 7.7% of the population under 5, 13.2% between 6–18, 69% - from 19 to 64, and 10.1% who were 65 years of age or older. The median age 34.2 years. Females made up 50.8% of the population and there were 100.1 males per 100 females. 86.5% of the population graduated high school, while 44.9% of the population had a bachelor's degree or higher. 7.1% of residents under 65 were disabled, while 15.9% of residents live without health insurance.

There were 110,801 housing units and 102,353 households in 2018. The average household size was 2.57. The average per capita income was $36,453, and the median household income was $62,739. 18.7% of residents lived below the poverty line. 67.9% of residents 16+ were within the civilian labor force. The mean travel time to work for residents was 36.8 minutes. 28.6% of housing units are owner-occupied, with the median value of the homes being $344,200. The median gross rent in the city was $1,271.

Jersey City is one of the most ethnically diverse cities in the world. The city is a major port of entry for immigration to the United States and a major employment center at the approximate core of the New York City metropolitan area; and given its proximity to Manhattan, Jersey City has evolved a globally cosmopolitan ambiance of its own, demonstrating a robust and growing demographic and cultural diversity with respect to metrics including nationality, religion, race, and domiciliary partnership.

There were an estimated 55,493 non-Hispanic whites in Jersey City, according to the 2013–2017 American Community Survey, representing a 4.2% increase from 53,236 non-Hispanic whites enumerated in the 2010 United States Census. Many non-Hispanic whites have settled in the newer developments in the Newport and Exchange Place neighborhoods along the Jersey City waterfront.

Ever since the settling of New Netherland in the 1600s, comprising what is now the Gateway Region of northeastern New Jersey as well as portions of Downstate New York in the New York City metropolitan area, the Dutch and British, along with German and Irish Americans, have established an integral role in the subsequent long-term development of Jersey City over the centuries. In 2012 the opening of The French American Academy downtown Jersey City has generated an inflow of French and European settlers from in-state and out-of-state as well as overseas origin.

An estimated 63,788 African Americans resided in Jersey City, or 24.0% of the city's population in 2017, representing a slight decrease from 64,002 African Americans enumerated in the 2010 United States Census. This is in contrast with Hudson County overall, where there were an estimated 84,114 African Americans, according to the 2013–2017 American Community Survey, representing a 2.3% increase from 83,925 African Americans enumerated in the county in the 2010 United States Census. However, modest growth in the African immigrant population, most notably the growing Nigerian American and Kenyan American populations in Jersey City, is partially offsetting the decline in the city's American-born black population, which as a whole has been experiencing an exodus from northern New Jersey to the Southern United States. Approximately 76,637 Latino and Hispanic Americans lived in Jersey City, composing 28.8% of the population in 2017, representing a 12.3% increase from 68,256 Latino or Hispanic Americans enumerated in the 2010 United States Census. Immigrants from South America, led by Ecuador, are a growing component of Jersey City's population.Stateside Puerto Ricans, making up a third of the city's Latin American or Hispanic population, constituted the largest Hispanic group in Jersey City. While Cuban Americans are not as highly concentrated in Jersey City as they are in northern Hudson County, Jersey City has hosted the annual Cuban Parade and Festival of New Jersey at Exchange Place on its downtown waterfront since it was established in 2001.

An estimated 67,526 Asian Americans live in Jersey City, constituting 25.4% of the city's population, representing a 15.2% increase from 58,595 Asian Americans enumerated in the 2010 United States Census.

India Square, also known as "Little India" or "Little Bombay", home to the highest concentration of Asian Indians in the Western Hemisphere, is a rapidly growing Indian American ethnic enclave in Jersey City. Indian Americans constituted 10.9% of the overall population of Jersey City in 2010, the highest proportion of any major U.S. city. India Square has been home to the largest outdoor Navratri festivities in New Jersey as well as several Hindu temples; while an annual, color-filled spring Holi festival has taken place in Jersey City since 1992, centered upon India Square and attracting significant participation and international media attention. In 2017 there were an estimated 31,578 Indian Americans in Jersey City, representing a 16.5% increase from 27,111 Indian Americans enumerated in the 2010 United States Census.

Filipino Americans, with 16,610 residents, made up 6.2% of Jersey City's population. The Five Corners district is home to a thriving Filipino community and Jersey City's Little Manila, which is the second-largest Asian American subgroup in the city. A variety of Filipino restaurants, shippers and freighters, doctors' officers, bakeries, stores, and an office of The Filipino Channel have made Newark Avenue their home. The largest Filipino-owned grocery store on the East Coast of the United States, Phil-Am Food, has been there since 1973. An array of Filipino-owned businesses can also be found at the section of West Side of Jersey City, where many of its residents are of Filipino descent. In 2006, a Red Ribbon pastry shop, one of the Philippines' most famous food chains, opened its first branch on the East Coast in the Garden State.Manila Avenue in Downtown Jersey City was named for the Philippine capital city because of the many Filipinos who built their homes on this street during the 1970s. A memorial, dedicated to the Filipino American veterans of the Vietnam War, was built in a small square on Manila Avenue. A park and statue dedicated to Jose P. Rizal, a national hero of the Philippines, is located in downtown Jersey City. Jersey City is the host of the annual Philippine-American Friendship Day Parade, an event that occurs yearly in June, on its last Sunday. The City Hall of Jersey City raises the Philippine flag in correlation to this event and as a tribute to the contributions of the Filipino community. The Santacruzan Procession along Manila Avenue has taken place since 1977.

Behind English and Spanish, Tagalog is the third-most-common language spoken in Jersey City.

Jersey City was home to an estimated 9,379 Chinese Americans in 2017, representing a notably rapid growth of 66.2% from the 5,643 Chinese Americans enumerated in the 2010 United States Census. Chinese nationals have also been obtaining EB-5 immigrant visas by investing US$500,000 apiece in new Downtown Jersey City residential skyscrapers.

New Jersey's largest Vietnamese American population resides in Jersey City. There were an estimated 1,813 Vietnamese Americans in Jersey City, according to the 2013–2017 American Community Survey, representing a 12.8% increase from 1,607 Vietnamese Americans enumerated in the 2010 United States Census.

Arab Americans numbered an estimated 18,628 individuals in Hudson County per the 2013–2017 American Community Survey, representing 2.8% of the county's total population. Arab Americans are the second- highest percentage in New Jersey after Passaic County. Arab Americans are most concentrated in Jersey City, led by Egyptian Americans, including the largest population of Coptic Christians in the United States. There is a notable Algerian and Moroccan American population in Jersey City.^{[citation needed]}

There were 2,726 same-sex couples in Hudson County in 2010, with Jersey City being the hub, prior to the commencement of same-sex marriages in New Jersey on October 21, 2013.

Nearly 60% of Jersey City's inhabitants are religious. The largest religious community in the city is Christianity, followed by Islam, the eastern religions, and Judaism.

The Catholic Church, served by the Roman Catholic Archdiocese of Newark, forms the largest Christian group in Jersey City (46.2%). The Catholic Church is also served by the Syriac Catholic Eparchy of Our Lady of Deliverance of Newark, an Eastern Catholic jurisdiction of the Syriac Catholic Church.

Baptists, primarily affiliated with the American Baptist Churches USA, National Baptist Convention, USA, Inc, and NBCA International, made up the second largest Christian group (2.9%). Pentecostals (1.0%), the Latter Day Saints (0.7%), Methodists (0.5%), and Lutherans (0.5%) make up the following Christian groups in the city. Presbyterians, primarily served by the Presbyterian Church (USA), and Anglicans or Episcopalians comprised 0.3% of the Christian demographic each. The largest Anglican or Episcopalian bodies in Jersey City are the Episcopal Diocese of Newark (Episcopal Church USA), and the Diocese of the Northeast and Mid-Atlantic (Anglican Church in North America and Reformed Episcopal Church). Christians of another faith, including the Eastern and Oriental Orthodox, Jehovah's Witnesses, non-denominational Protestants, and ISM churches made up 1.8% of the city's Christians.

Muslims constituted 3.4% of religious adherents in Jersey City. They make up a growing Muslim American population in Jersey City and Hudson County.^{[clarification needed]} Local Latino and Hispanics have been the largest demographic converting to Islam after Black or African Americans.Pakistani Americans, Bangladeshi Americans, and Arab Americans compose a significant proportion of Jersey City's Muslim population. The largest branches of Islam practiced are Sunni Islam, Shia Islam, and Ahmadiyya, though some Quranist and non-denominational Muslims practice their faith in the city and surrounding area.

Eastern religions including Buddhism, Hinduism and Sikhism made up 1.5% of the city's religious demographic, and Judaism is the fourth largest religious community in Jersey City (0.6%). Jersey City has a growing Orthodox Jewish population, centered in the Greenville neighborhood.