Waterbury is a city in the U.S. state of Connecticut. Waterbury had a population of 114,403 as of the 2020 Census. The city is 33 miles (53 km) southwest of Hartford and 77 miles (124 km) northeast of New York City. Waterbury is the largest city in the Naugatuck Valley Planning Region and second-largest city in New Haven County.

Throughout the first half of the 20th century, Waterbury had large industrial interests and was the leading center in the United States for the manufacture of brassware (including castings and finishings), as reflected in the nickname the "Brass City" and the city's motto Quid Aere Perennius? ("What Is More Lasting Than Brass?"). It was also noted for the manufacture of watches and clocks (Timex).

The city is alongside Interstate 84 (Yankee Expressway) and Route 8 and has a Metro-North railroad station with connections to Grand Central Terminal. Waterbury is also home to Post University and the regional campuses of the University of Connecticut, University of Bridgeport, Western Connecticut State University as well as Naugatuck Valley Community College.

The land was originally inhabited by the Algonquin bands. According to Samuel Orcutt's history, some Puritan residents of nearby Farmington "found it expedient to purchase the same lands from different tribes, without attempting to decide between their rival claims." The original settlement of Waterbury in 1674 was in the area now known as the Town Plot section. In 1675, the turbulence of King Philip's War caused the new settlement to be vacated until the resumption of peace in 1677. A new permanent location was found across the river to the east along the Mad River. The original Native American inhabitants called the area "Matetacoke" meaning "the interval lands." Thus, the settlement's name was Anglicised to "Mattatuck" in 1673. When the settlement was admitted as the 28th town in the Connecticut Colony in 1686, the name was changed to Waterbury in reference to the numerous streams that emptied into the Naugatuck River from the hills on either side of the valley. At that time, it included all or parts of what later became the towns of Watertown, Plymouth, Wolcott, Prospect, Naugatuck, Thomaston, and Middlebury.

Growth was slow during Waterbury's first hundred years, the lack of arable land due to the constant flooding of the Naugatuck River in particular, discouraged many potential settlers. Furthermore, the residents suffered through a great flood in 1691 and an outbreak of disease in 1712. After a century, Waterbury's population numbered just 5,000.

Waterbury emerged as an early American industrial power in the early 19th century when the city began to manufacture brass, harnessing the waters of the Mad River and Naugatuck River to power the early factories. The new brass industry attracted many immigrant laborers from all over the world, leading to an influx of diverse nationalities. Waterbury was incorporated as a city in 1853 and, as the "Brass Capital of the World", it gained a reputation for the quality and durability of its goods. Brass and copper supplied by Waterbury were used in Nevada's Boulder Dam among myriad applications across the United States.

A famous Waterbury product of the late-19th century was Robert H. Ingersoll's one-dollar pocket watch, five million of which were sold. After this, the clock industry became as important as Waterbury's brass industry. Evidence of these industries can still be seen in Waterbury, as numerous clocktowers and old brass factories have become landmarks of the city.

Waterbury produced silverware starting in 1858 by Rogers & Brother, and in 1886 by Rogers & Hamilton. In 1893, Rogers & Brother exhibited wares at the World's Columbian Exposition in Chicago. In 1898, both companies became part of the International Silver Company, headquartered in nearby Meriden. Production continued at the R&B site until 1938. Designs of the two companies are in the collections of the Mattatuck Museum in Waterbury, the Brooklyn Museum in New York, the Yale University Art Gallery in New Haven, and in many historical societies and museums across the United States.

In June 1920, labor unrest occurred, with striking workers fighting with police on the street. Over 30 were arrested, mostly Lithuanians, Russians, Poles, and Italians. The strikers numbered some 15,000, with most being employed at Scovill, Chase Rolling Mill, and Chase Metal Works. One striker was shot to death by police.

At its peak during World War II, 10,000 people worked at the Scovill Manufacturing Co, later sold to Century Brass. The city's metal manufacturing mills (Scovill Manufacturing, Anaconda American Brass, and Chase Brass & Copper were the largest) occupied more than 2 million square feet (180,000 m2) and more than 90 buildings.

On May 24, 1962, the north side of the city was devastated by a high-end F3 tornado that caused widespread damage, destroyed numerous neighborhoods, and left one dead and 50 injured. Damage from the storm was estimated to be at least $5 million.

According to the United States Census Bureau, the city has a total area of 29.0 square miles (75.0 km2), of which 28.5 square miles (73.9 km2) is land and 0.42 square miles (1.1 km2), or 1.46%, is water.

Waterbury lies in the humid continental climate zone, and normally sees cold, snowy winters and warm, humid summers.

Waterbury's neighborhoods are shaped by the history and geography of the city.

Ethnic communities distinguish the city's 25 neighborhoods. Clusters of shops at the street corners created villages within the city. For many people, home, work and community life was contained within their neighborhood. Downtown, a short walk away, was "the city", offering live theater, fancy stores, parades and spectacles.

As of the census of 2010, there were 110,366 people, 42,761 households, and 26,996 families residing in the city. The population density was 3,866 inhabitants per square mile (1,493/km2). There were 42,761 housing units at an average density of 1,492.0 per square mile. The racial makeup of the city was 58.8% White, 20.1% Black or African American, 0.6% Native American, 1.8% Asian, 0.1% Pacific Islander, 14.2% from other races, and 4.6% from two or more races. Hispanic or Latino people of any race were 31.2% of the population.

Waterbury has a large Italian-American population with 21.46% of its residents claiming Italian heritage. The Italian influence is especially strong in the Town Plot, Brooklyn, and North End neighborhoods. Additionally, the city is home to thriving Albanian, Cape Verdean, Dominican, Brazilian, Jamaican, Lithuanian, Portuguese, and Puerto Rican communities. Waterbury also has a large Irish community, especially in the Washington Hill section which is home to the city's annual St. Patrick Day's Parade, which, oddly enough, is rarely held on St. Patrick's Day itself. At the beginning of the 21st century, Waterbury had a growing Orthodox Jewish population. Waterbury had a significant Jewish population beginning in the late 1800s, initially as a result of German immigration. The first synagogue in Waterbury opened in 1872. In the early 20th century, almost 9,000 Jews immigrated from Eastern Europe, with many fleeing persecution. The Orthodox Jewish community has experienced a renaissance since 2000 due to efforts by educators and developers to create an affordable alternative to the high cost of living in established Orthodox communities in New York and New Jersey. This renaissance began with the founding of the Yeshiva K'tana of Waterbury in 2000; as of 2014, this full-service elementary and middle school has nearly 400 students. Other educational institutions are the Yeshiva Gedolah of Waterbury, which includes a mesivta high school and beit medrash (undergraduate) program for approximately 230 students, a Bais Yaakov school for girls, and a kolel. As of the end of 2014, the Waterbury Orthodox community numbers 180 families and includes a mikveh, eruv, and community services such as Hatzalah and Chaverim.

There were 42,622 households, out of which 31.2% had children under the age of 18 living with them, 34.7% were married couples living together, 28.4% had a single householder with no husband present, and 36.9% were non-families. 31.4% of all households were made up of individuals, and 12.1% had someone living alone who was 65 years of age or older. The average household size was 2.46 and the average family size was 3.11.

In the city, the population was spread out, with 25.6% under the age of 18, 10.1% from 18 to 24, 27.4% from 25 to 44, 24.3% from 45 to 64, and 12.6% who were 65 years of age or older. The median age was 35.2 years. For every 100 females, there were 89.9 males. For every 100 females age 18 and over, there were 85.8 males.

According to the 2014 5-year American Community Survey (conducted 2010–2014, data released December 3, 2015), the median income for a household in the city was $41,136, compared to $69,899 statewide. In Waterbury, 24.2% of the population, or 26,122 residents of the city, lived below the poverty line, compared to 10.5% statewide. In Waterbury, 36.8% of the child population age 0–17, or 9,984 children in the city, lived below the poverty line, compared to 14% statewide.

Waterbury's economic decline in the 1970s and 1980s resulted in it being ranked as having the worst quality of life of 300 U.S. metropolitan areas by Money Magazine in 1992. Waterbury was also rated as one of the "Worst Places for Businesses and Careers in America" by Forbes Magazine in April 2008. Regardless, the city was named on the 100 Best Places to Raise a Family list in the same year.

According to the city's 2022 Comprehensive Annual Financial Report, the top employers in the city are:

Waterbury has about 52,000 registered voters, of whom about 24,000 are Democrats. There are about 7,800 registered Republicans and the balance are largely unaffiliated, with a smattering belonging to minor parties.

John S. Monagan, who was a prolific author in addition to his political responsibilities, served as Waterbury's mayor from 1943 to 1948. He also served as its district's congressional representative from 1959 to 1973. George Harlamon, a member of the Waterbury Hall of Fame, was the city's 40th mayor. He served from 1969 to 1970 during a period of racial tension. The city is known for its hard-nosed political culture compared locally to Cook County, Illinois, close elections, and a number of scandals.

Waterbury's scandalous past dates back to 1940, when Mayor T. Frank Hayes and 22 others were convicted of conspiracy to defraud the City of Waterbury. Hayes received a 10–15 year sentence and served six years. Ironically, the massive corruption scheme was exposed with the help of then comptroller Sherwood Rowland, grandfather of Gov. John G. Rowland, who was convicted on corruption charges in 2004. What appeared to have been a defeat for Hayes was not really a victory for Pape, and the stage was set for further corruption in Waterbury in the second half of the 20th century. Waterbury was in serious financial straits due to years of mismanagement, resulting in the city's finances being taken over by the State of Connecticut. The State Oversight Board oversaw city business for several years and have since left following consecutive years of balanced budgets. In 1992 former Mayor Joseph Santopietro was sentenced to nine years in prison following a public corruption conviction. The successors to Philip Giordano, former acting mayor Sam Caligiuri (2001) and former mayor Michael Jarjura (2001–2011) managed the city without major controversy since 2001. Democrat Neil O'Leary was elected the 46th Mayor of Waterbury on November 9, 2011.

In 1939, Pape backed an attempt to install council-manager government and single-transferable-vote elections. The local Republican Party and Connecticut General Assembly also supported this measure. New York Mayor Fiorello H. La Guardia helped campaign for its passage, having backed similar reforms in his own city in 1936.

A number of presidential candidates have campaigned in Waterbury due to its pivotal role in statewide elections. The most famous was the election eve visit on the Green by John F. Kennedy in 1960. Forty thousand people waited until 3am on the Green to greet Kennedy on Sunday, November 6, 1960. Sen. Kennedy spoke to them from the balcony of the Roger Smith Hotel (now called the Elton). Pierre Salinger later said it was the greatest night of the campaign. In September 1984 Ronald Reagan held a huge noontime election rally at the same location. In July 2006 former president Bill Clinton made a campaign appearance at the Palace Theatre for Senator Joe Lieberman during his campaign for re-election to the U.S. Senate. Shortly after the Democratic primary, Tom Swan, campaign manager for Lieberman's opponent Ned Lamont, described Waterbury as a place where "the forces of slime meet the forces of evil," after a large majority of the town's voters backed Lieberman. Swan claimed he was referring to former mayor Philip A. Giordano and former governor John G. Rowland.

Governor John G. Rowland served ten months in a federal prison until February 10, 2006. He was released from federal prison with the stipulation that he serve four months house arrest with an electronic ankle bracelet monitor until June 2006.

In January 2008 Waterbury Mayor Michael Jarjura announced that he would hire Rowland as an economic development advisor for the city. Rowland began work in February that year receiving an annual salary of $95,000 as the city's economic development coordinator funded in conjunction with the Greater Waterbury Chamber of Commerce.

In 2011, the Board of Aldermen voted to eliminate funding the city's portion of his salary and in November 2011 Rowland stated he would give up his position when his contract expired thus ending his quasi-city employment.

Later that year, following his victory over then Mayor Jarjura, new mayor Neil O'Leary created the position of Economic Development Director as part of his new administration, removing the duties from the Chamber of Commerce and bringing them directly into City Hall, making Economic Development a cornerstone of his administration. Ron Pugliese was hired as the first director to hold the position.

Public schools are operated by Waterbury Public Schools, under the leadership of a superintendent and a board of education consisting of ten elected members and the city mayor, who acts as chairman ex-officio. Schools include:

Two newspapers are operated within Waterbury: the Republican-American, which covers 36 communities throughout Western Connecticut, and the Waterbury Observer. WATR 1320 AM, a radio station under the same family ownership since 1934 and broadcasting on the same frequency since 1939, operates a News/Talk/Classic Hits music format and is the only radio station broadcasting in Waterbury. Two FM radio stations are also located in Waterbury: WWYZ 92.5, which plays a country music format and WMRQ 104.1, which plays alternative rock. They both transmit from 10 miles away in Meriden and have wide-reaching signals that can be heard clearly as far away as Bridgeport and the Massachusetts state line.

WCCT-TV (channel 20) is licensed to Waterbury and serves as Hartford's affiliate for The CW; it is operated out of the Hartford Courant building with sister Tribune Broadcasting Fox affiliate WTIC-TV (channel 61), and carries mainly syndicated content outside of network hours. Waterbury is considered part of the Hartford/New Haven media market, and can thus receive radio and television signals from Hartford and New Haven clearly.

Commuting in the Greater Waterbury area consists of multiple public transportation options. CT Transit through Northeast Transportation Company, operates a significant number of city buses running from Waterbury's city center at Exchange Place to various neighborhoods in the city. In 2014 the Hartford-New Britain Busway was opened, a local bus runs to Waterbury, Cheshire, Southington and New Britain an express bus to run between Waterbury and Hartford.

Metro-North Railroad runs commuter trains multiple times a day between the Waterbury station and Bridgeport, with connections to Grand Central Terminal in New York City. Waterbury's Union Station, built in 1909 for the New York, New Haven and Hartford Railroad, is now closed for use as a railway station and part of the building is now the headquarters of the Republican-American newspaper. Passengers traveling to and from Waterbury board and alight on a concrete platform adjacent to the old station. There are no ticket agents at Waterbury, which is currently the end of the line for the Waterbury Branch.

The two main highways that run through the heart of the city are I-84 (Yankee Expressway) and Route 8. In the downtown area, I-84 and Route 8 are located on the elevated William W. Deady Bridge, known locally as the "MixMaster" with eastbound traffic on the upper deck and westbound traffic on the lower deck. The interchange is ranked as one of the most heavily congested traffic areas in the New York/Connecticut region. Waterbury–Oxford Airport is the primary airport serving the city. The smaller Waterbury Airport is about 4 miles (6.4 km) from the city's central business district. Bradley International Airport (BDL) in Windsor Locks and Tweed New Haven Airport (HVN) in East Haven are the closest commercial airports to Waterbury.

The Waterbury Police Department was founded in 1853. The department has a police academy.

Waterbury Fire Department is a full-time, paid fire department, which operates eight engine companies, three truck companies, one squad company, and one rescue company out of nine fire stations, divided into 2 battalions. One battalion is commanded by a Battalion Chief, and the other a Deputy Chief, who serves as the Tour Commander each shift.