Paterson (English pronunciation: /ˈpætɚsən/ ^ⓘ ) is the largest city in and the county seat of Passaic County, in the U.S. state of New Jersey. As of the 2020 United States census, Paterson was the state's third-most-populous municipality, with a population of 159,732, an increase of 13,533 (+9.3%) from the 2010 census count of 146,199, which in turn reflected a decline of 3,023 (-2.0%) from the 149,222 counted in the 2000 census. The Census Bureau's Population Estimates Program calculated a population of 156,452 for 2023, making it the 168th-most populous municipality in the nation.

A prominent mill town within the New York–New Jersey metropolitan area, Paterson has been known as Silk City for its once-dominant role in silk production during the latter half of 19th century. It has since evolved into a major destination for Hispanic immigrants as well as for immigrants from Turkey, the Arab world, and South Asia. Paterson has the nation's second-largest per capita Muslim population.

The area of Paterson was inhabited by the Algonquian-speaking Native American Acquackanonk tribe of the Lenape, also known as the Delaware Indians. The land was known as the Lenapehoking. The Dutch claimed the land as New Netherlands, followed by the British as the Province of New Jersey.

In 1791, Alexander Hamilton (1755/57–1804), first United States Secretary of the Treasury, helped found the Society for Establishing Useful Manufactures (S.U.M.), which helped encourage the harnessing of energy from the Great Falls of the Passaic River to secure economic independence from British manufacturers. The society founded Paterson, which became the cradle of the Industrial Revolution in America. Paterson was named for William Paterson, statesman, signer of the Constitution and Governor of New Jersey, who signed the 1792 charter that established the Town of Paterson.

Architect, engineer and city planner Pierre L'Enfant (1754–1825), who had earlier developed the initial plans for Washington, D.C., was the first planner for the S.U.M. project. His plan proposed to harness the power of the Great Falls through a channel in the rock and an aqueduct. The society's directors felt he was taking too long and was over budget; he was replaced by Peter Colt, who used a less complicated reservoir system to get the water flowing to factories in 1794. Eventually, Colt's system developed some problems and a scheme resembling L'Enfant's original plan was used after 1846.

Paterson was originally formed as a township from portions of Acquackanonk Township on April 11, 1831, while the area was still part of Essex County. It became part of the newly created Passaic County on February 7, 1837, and was incorporated as a city on April 14, 1851, based on the results of a referendum held that day. The city was reincorporated on March 14, 1861.

The 77-foot-high (23 m) Great Falls and a system of water raceways that harnessed the falls' power provided power for the mills in the area until 1914 and fostered growth of the city. The district originally included dozens of mill buildings and other manufacturing structures associated with the textile industry and, later, the firearms, silk, and railroad locomotive manufacturing industries. In the latter half of the 19th century, silk production became the dominant industry and formed the basis of Paterson's most prosperous period, earning it the nickname "Silk City."

In 1835, Samuel Colt began producing firearms in Paterson, but within a few years moved his business to Hartford, Connecticut. Later in the 19th century, Paterson was the site of early experiments with submarines by Irish-American inventor John Philip Holland. Two of Holland's early models—one found at the bottom of the Passaic River—are on display in the Paterson Museum, housed in the former Rogers Locomotive and Machine Works near the Passaic Falls.