Bridgeport was inhabited by the Paugussett native American tribe during the start of European colonization. The earliest European communal settlement was in the historical Stratfield district, along US Route 1; known in colonial times as the King's Highway. Close by, Mount Grove Cemetery was laid out on what was a native village that extended past the 1650s. It is also an ancient Paugusett burial ground.

The burgeoning farming community grew and became a center of trade, shipbuilding, and whaling. The town incorporated to subsidize the Housatonic Railroad and rapidly industrialized following the rail line's connection to the New York and New Haven railroad. The namesake of the town was the need for bridges over the Pequonnock River that provided a navigable port at the mouth of the river. Manufacturing was the mainstay of the local economy until the 1970s.

The first documented European settlement within the present city limits of Bridgeport took place in 1644, centered at Black Rock Harbor and along North Avenue between Park and Briarwood Avenues. The place was called Pequonnock (Quiripi for "Cleared Land"), after a band of the Paugussett, an Algonquian-speaking Native American people who occupied this area. One of their sacred sites was Golden Hill, which overlooked the harbor and was the location of natural springs and their planting fields. (It has since been blasted through for construction of an expressway.) The Golden Hill Indians were granted a reservation here by the Colony of Connecticut in 1639; it lasted until 1802. (One of the tribes acquired land for a small reservation in the late 19th century that was recognized by the state. It is retained in the Town of Trumbull.)

Bridgeport's early years were marked by residents' reliance on fishing and farming. This was similar to the economy of the Paugusset, who had cultivated corn, beans, and squash; and fished and gathered shellfish from both the river and sound. A village called Newfield began to develop around the corner of State and Water streets in the 1760s. The area officially became known as Stratfield in 1695 or 1701, due to its location between the already existing towns of Stratford and Fairfield. During the American Revolution, Newfield Harbor was a center of privateering.

By the time of the State of Connecticut's ratification of the Articles of Confederation in 1781, many of the local farmers held shares in vessels trading at Newfield Harbor or had begun trading in their own name. Newfield initially expanded around the coasting trade with Boston, New York, and Baltimore and the international trade with the West Indies. The commercial activity of the village was clustered around the wharves on the west bank of the Pequonnock, while the churches were erected inland on Broad Street. In 1800, the village became the Borough of Bridgeport, the first so incorporated in the state. It was named for the Newfield or Lottery Bridge across the Pequonnock, connecting the wharves on its east and west banks. Bridgeport Bank was established in 1806. In 1821, the township of Bridgeport became independent of Stratford.

The West India trade died down around 1840, but by that time the Bridgeport Steamship Company (1824) and Bridgeport Whaling Company (1833) had been incorporated and the Housatonic Railroad chartered (1836). The HRRC ran upstate along the Housatonic Valley, connecting with Massachusetts's Berkshire Railroad at the state line. Bridgeport was chartered as Connecticut's fifth city in 1836 in order to enable the town council to secure funding (ultimately $150,000) to provide to the HRRC and ensure that it would terminate in Bridgeport. The Naugatuck Railroad—connecting Bridgeport to Waterbury and Winsted along the Naugatuck—was chartered in 1845 and began operation four years later. The same year, the New York and New Haven Railroad began operation, connecting Bridgeport to New York and the other towns along the north shore of the Long Island Sound.

Now a major junction for western Connecticut, the city rapidly industrialized. Following the Civil War, it held several iron foundries and factories manufacturing firearms, metallic cartridges, horse harnesses, locks, and blinds.Wheeler & Wilson's sewing machines were exported throughout the world. Bridgeport annexed the West End and the village of Black Rock and its busy harbor in 1870. In 1875, P. T. Barnum was elected mayor of the town, which afterwards served as the winter headquarters of Barnum and Bailey's Circus and Buffalo Bill's Wild West Show.

From 1870 to 1910, Bridgeport became the major industrial center of Connecticut and its population rose from around 25,000 to over 100,000, including thousands of Irish, Slovaks, Hungarians, Germans, English, and Italian immigrants.

Among the initiatives, the Singer factory joined Wheeler & Wilson in producing sewing machines and the Locomobile Company of America was a prominent early automobile manufacturer, producing a prototype of the Stanley Steamer and various luxury cars.

Further, the Holmes & Edwards Silver Co. was founded in 1882, with its wares sold nationally, and the company became part of the International Silver Company in 1898. (The H&E brand, in fact, continued well into the 1950s and was advertised in national magazines such as LIFE and Ladies' Home Journal.)

The town was also the center of America's corset production, responsible for almost 20% of the national total, and became the headquarters of Remington Arms following its 1912 merger with the Union Metallic Cartridge Co. Around the time of the First World War, Bridgeport was also producing steam-fitting and heating apparatuses, brass goods, phonographs, typewriters, milling machines, brassieres, and saddles.

In the summer of 1915, a series of strikes imposed the eight-hour day on the town's factories; rather than moving business elsewhere, the success spread the eight-hour day throughout the Northeast. The First World War continued the city's expansion so that, on the eve of the Great Depression, there were more than 500 factories in Bridgeport, including Columbia Records' primary pressing plant. The build-up to World War II helped its recovery in the late 1930s.

Restructuring of heavy industry starting after the mid-20th century caused the loss of thousands of jobs and residents. Like other urban centers in Connecticut, Bridgeport suffered during the deindustrialization of the United States in the 1970s and 1980s. Continued development of new suburban housing attracted middle and upper-class residents, leaving the city with a higher proportion of poor. The city suffered from overall mismanagement, for which several city officials were convicted, contributing to the economic and social decline. In September 1978, Bridgeport teachers went on a 19-day strike due to deadlocked contract negotiations. A court order, as well as a state law that made strikes by public workers illegal in Connecticut, resulted in 274 teachers being arrested and jailed. Bridgeport made numerous efforts at revitalization. In one proposal, Las Vegas developer Steve Wynn was to build a large casino, but that project failed. In 1991, the city filed for bankruptcy protection but was declared solvent by a federal court.

In the early 21st century, Bridgeport has taken steps toward redevelopment of its downtown and other neighborhoods. In 2004, artists' lofts were developed in the former Read's Department Store on Broad Street. Several other rental conversions have been completed, including the 117-unit Citytrust bank building on Main Street. The recession halted, at least temporarily, two major mixed-use projects including a $1-billion waterfront development at Steel Point, but other redevelopment projects have proceeded, such as the condominium conversion project in Bijou Square. In 2009, the City Council approved a new master plan for development, designed both to promote redevelopment in selected areas and to protect existing residential neighborhoods. In 2010, the Bridgeport Housing Authority and a local health center announced plans to build a $20 million medical and housing complex at Albion Street, making use of federal stimulus funds and designed to replace some of the housing lost with the demolition of Father Panik Village. Recently, MGM announced plans to build a waterfront casino and shopping center in the city, awaiting approval by the state government. If built, the development will create 2,000 permanent jobs and about 5,779 temporary jobs.

On March 10, 1860, Abraham Lincoln spoke in the city's Washington Hall, an auditorium at the old Bridgeport City Hall (now McLevy Hall), at the corner of State and Broad Streets. The largest room in the city was packed, and a crowd formed outside, as well. Lincoln received a standing ovation before taking the 9:07 pm train that night back to Manhattan. A plaque marks the site where Lincoln spoke; later that year, he was elected president.

The Rev. Martin Luther King, Jr. spoke three times at the Klein Auditorium during the 1960s. Additionally, President George W. Bush spoke before a small group of Connecticut business people and officials at the Playhouse on the Green in 2006. President Barack Obama also spoke at the Harbor Yard arena in 2010 to gain support for the campaign of Democratic Governor Dan Malloy.

On April 23, 2016, Republican presidential candidate Donald Trump spoke to supporters at the Klein Memorial Auditorium during the 2016 Republican Party presidential primaries.

As of the census of 2000, there were 139,529 people, 50,307 households, and 32,749 families living in the city. The population density was 8,720.9 people per square mile (3,367.0/km²). There were 54,367 housing units at an average density of 3,398.1 per square mile (1,312.0/km²). The racial makeup of the city was 45.0% White, 30.8% African American, 0.5% Native American, 3.3% Asian, 0.1% Pacific Islander. Hispanic or Latino of any race were 20.3% of the population. Other ancestry groups include: Italian (8.6%), Irish (5.1%), Portuguese (2.9%), Polish (2.8%), and German (2.4%).

As of the 2010 census, there were 144,229 people living in the city. The racial makeup of the city residents was 39.6% White; 34.6% Black or African American; 3.4% Asian; and 4.3% from two or more races. A total of 38.2% of the population were Hispanic or Latino of any race.

There were 50,307 households, out of which 34.3% had children under the age of 18 living with them, 35.0% were married couples living together, 24.0% had a female householder with no husband present, and 34.9% were non-families. 29.0% of all households were made up of individuals, and 11.3% had someone living alone who was 65 years of age or older. The average household size was 2.70 and the average family size was 3.34.

In the city, the population was spread out, with 28.4% under the age of 18, 11.2% from 18 to 24, 30.5% from 25 to 44, 18.4% from 45 to 64, and 11.5% who were 65 years of age or older. The median age was 31 years. For every 100 females, there were 91.2 males. For every 100 females age 18 and over, there were 86.3 males.

The median income for a household in the city was $34,658, and the median income for a family was $39,571. Males had a median income of $32,430 versus $26,966 for females. The per capita income for the city was $16,306. About 16.2% of families and 18.4% of the population were below the poverty line, including 24.8% of those under age 18 and 13.2% of those age 65 or over.

According to 2010 census data, the Bridgeport MSA, containing all of Fairfield County, is the most economically unequal region in America, with 57% of the wealth going to the top income quintile.