The earliest residents of what is now Inglewood were Native Americans who used the natural springs in today's Edward Vincent Jr. Park (known for most of its history as Centinela Park). Local historian Gladys Waddingham wrote that these springs took the name Centinela from the hills that rose gradually around them and which allowed ranchers to watch over their herds "(thus the name centinelas or sentinels)".^:unpaged

Waddingham traced the written history of Inglewood back to the original settlers of Los Angeles in 1781, one of whom was the Spanish soldier Jose Manuel Orchado Machado, "a 23-year-old muleteer from Los Alamos in Sinaloa". These settlers, she wrote, were ordered by the officials of the San Gabriel Mission "to graze their animals on the ocean side of Los Angeles in order not to infringe on Mission lands." As a result, the settlers, or pobladores, drove some of their cattle to the "lush pasture lands near Centinela Springs", and the first construction there was done by Ygnacio Avila, who received a permit in 1822 to build a "corral and hut for his herders."^:unpaged

Later Avila constructed a three-room adobe on a slight rise overlooking the creek that ran from Centinela Springs all the way to the ocean. According to the LAOkay web site, this adobe was built where the present baseball field is in the park. It no longer exists.

In 1834, Ygnacio Machado, one of the sons of Jose Machado, built the Centinela Adobe,^:unpaged which sits on a rise above the present Interstate 405 (San Diego Freeway) and is used as the headquarters of the Centinela Valley Historical Society. Two years later, Waddingham writes, Ygnacio was granted the 2,220-acre (9.0 km²) Rancho Aguaje de la Centinela even though this land had already been claimed by Avila.^:unpaged

Daniel Freeman acquired the rancho and was a founder of the Centinela-Inglewood Land Company in 1887, which developed the city.

Inglewood Park Cemetery, a widely used cemetery for the entire region, was founded in 1905. The city has been home to the Hollywood Park Racetrack from 1938 to 2013, one of the premier horse racing venues in the United States.Fosters Freeze, the first soft serve ice cream chain in California, was founded by George Foster in 1946 in Inglewood. Inglewood was named an All-America City by the National Civic League in 1989 and yet again in 2009 for its visible progress.

Ku Klux Klan activities in Inglewood during the 20th century were highlighted by the 1922 arrest and trial of 37 men, most of them masked, for a night-time raid on a suspected bootlegger and his family. The raid led to the shooting death of one of the culprits, an Inglewood police officer. A jury returned a "not guilty" verdict for all defendants who completed the trial. It was this scandal, according to the Los Angeles Times, that eventually led to the outlawing of the Klan in California. The Klan had a chapter in Inglewood as late as October 1931.

"No blacks had ever lived in Inglewood", Gladys Waddingham wrote,^:59 but by 1960, "they lived in great numbers along its eastern borders. This came to the great displeasure of the predominantly white residents already residing in Inglewood. In 1960, the census counted only 29 'Negroes' among Inglewood's 63,390 residents. Not a single black child attended the city's schools. Real estate agents refused to show homes to blacks. A rumored curfew kept blacks off the streets at night. Inglewood was a prime target because of its previous history of restrictions." "Fair housing and school busing were the main problems of 1964. The schools were not prepared to handle racial incidents, even though any that occurred were very minor. Adults held many heated community meetings, since the Blacks objected to busing as much as did the Whites."^:61 In 1969, an organization called "Morningside Neighbors" changed its name to "Inglewood Neighbors" "in the hope of promoting more integration."^:63

On February 3, 1969, Harold P. Moret (of Louisiana Creole Ancestry) became Inglewood's first black police officer. A full year later Jimmy Lee Worsham became the second. He was followed by Barbara Harris, the first black female officer, then Otis Hendricks, Melvin Lovelace and Eugene Lindsey. The seventh black officer was James T. Butts Jr. He became Inglewood's first black Motorcycle Traffic Enforcement Officer, first black lieutenant, captain and only black deputy chief in the history of the department. Butts left Inglewood in September 1991 at the age of 38 to become the first person of color to command the Santa Monica Police Department as Chief of Police, and the youngest ever to do so. Twenty years later, on February 1, 2011, Butts returned to Inglewood by being elected as its fourth black mayor.^{[citation needed]}

On July 22, 1970, Los Angeles Superior Court Judge Max F. Deutz ordered Inglewood schools to desegregate in response to a suit filed by 19 parents. At least since 1965, said Deutz, the Inglewood school board had been aware of a growing influx of black families into its eastern areas but had done nothing about the polarization of its pupils into an eastern black area and a western white one. On August 31, he rejected an appeal by four parents who said the school board was not responsible for the segregation but that the blacks "selected their places of residence by voluntary choice."

The first black principal among the 18 Inglewood schools was Peter Butler at La Tijera Elementary,^:66 and in 1971, Waddingham wrote, "Stormy racial meetings in 1971" included a charge by "some real estate men in the overflowing Crozier Auditorium" that the Human Relations Commission was acting like "the Gestapo."^:67 In that year, Loyd Sterling Webb, president of Inglewood Neighbors, became the first black officeholder when voters elected him to the school board.

In 1972, Curtis Tucker Sr. was appointed as the first black City Council member.^:69 That year composer LeRoy Hurte, an African-American, took the baton of the Inglewood Symphony Orchestra and continued to work with it for 20 years.^:75Edward Vincent Jr. became Inglewood's first black mayor in 1983. In that decade, whites left the city in increasing numbers, and Inglewood became the first city in California to declare the birthday of Martin Luther King Jr. a holiday.^:76 Since the term of Edward Vincent Jr. (1983–1997), Inglewood has consecutively elected African-American mayors: Roosevelt F. Dorn (1997–2010), Danny Tabor (2010–2011), and James T. Butts Jr. (2011–Present).

The 1990 census showed that Hispanics in Inglewood had increased by 134 percent since 1980, the largest jump in the South Bay. Economic factors apparently played a role in where new arrivals settled, said David Heer, a USC professor of sociology and associate director of the university's Population Research Laboratory. "Housing is generally less expensive here than elsewhere . . . and I would say that they receive a warmer welcome here", said Norm Cravens, assistant city manager in Inglewood, where the Anglo population dropped from nearly 21 percent in 1980 to 8.5 percent in 1990.

In the 2000 census, blacks made up 47 percent of the city's residents (53,060 people), and Hispanics comprised 46 percent (51,829), but the Census Bureau estimated that in 2007 the percentage of blacks had declined to 41 percent (48,252) and that of Hispanics of any race were at 52.5 percent (61,847). The white population declined from 19 percent (21,505) to 17.7 percent (20,853).

But that year, only one of the city's five City Council members was Latino: Jose Fernandez. There were no Latinos on the five-member Board of Education.

The 2010 United States Census reported that Inglewood had a population of 109,673. The population density was 12,062.1 people per square mile (4,657.2/km²). The racial makeup of Inglewood was 55,449 (50.6%) Hispanics or Latinos (of any race), 48,165 (43.9%) African American, 25,563 (23.3%) White (2.9% Non-Hispanic White), 751 (0.7%) Native American, 1,484 (1.5%) Asian, 350 (0.3%) Pacific Islander, 28,860 (26.3%) from other races, and 4,502 (4.1%) from two or more races. The Census reported that 108,171 people (98.6% of the population) lived in households, 987 (0.9%) lived in non-institutionalized group quarters, and 515 (0.5%) were institutionalized.

There were 36,389 households, out of which 15,315 (42.1%) had children under the age of 18 living in them, 13,095 (36.0%) were married couples living together, 8,987 (24.7%) had a female householder with no husband present, and 2,937 (8.1%) had a male householder with no wife present. There were 2,318 (6.4%) unmarried partnerships, and 234 (0.6%) same-sex partnerships, and 9,346 households (25.7%) were made up of individuals, and 2,776 (7.6%) had someone living alone who was 65 years of age or older. The average household size was 2.97. There were 25,019 families (68.8% of all households); the average family size was 3.59.

The age distribution was spread out, with 29,293 people (26.7%) under the age of 18, 11,853 people (10.8%) aged 18 to 24, 31,650 people (28.9%) aged 25 to 44, 26,621 people (24.3%) aged 45 to 64, and 10,256 people (9.4%) who were 65 years of age or older. The median age was 33.4 years. For every 100 females, there were 90.6 males. For every 100 females age 18 and over, there were 86.8 males.

There were 38,429 housing units at an average density of 4,226.5 per square mile (1,631.9/km²), of which 13,447 (37.0%) were owner-occupied, and 22,942 (63.0%) were occupied by renters. The homeowner vacancy rate was 1.5%; the rental vacancy rate was 5.5%, while 43,040 people (39.2% of the population) lived in owner-occupied housing units and 65,131 people (59.4%) lived in rental housing units.

According to the 2010 United States Census, Inglewood had a median household income of $43,394, with 22.4% of the population living below the federal poverty line.

Inglewood's population of 129,900 in 2006 was relatively youthful, with a median age of 31, compared to 36 in the nation as a whole. Eleven percent of its residents were under 5 years of age, as against 7 percent in the rest of the country. Some 8 percent were 65 or older, versus 12 percent elsewhere.

It was a city of renters squeezing into a limited amount of space. Of Inglewood's 37,562 occupied housing units (houses and apartments), just 39 percent were owned by the people who lived in them (compared to 67 percent in the U.S. as whole). The other units were rented out. Only 5 percent of its housing units were vacant, much less than the 12 percent across the country. The number of people living in each unit was about 3.7 persons, versus 2.7 elsewhere. Family size was 3.9 people, compared to 3.2.

It was estimated that 18 percent of Inglewood families had incomes below the poverty level, about twice that of the country at large (9 percent).

About 17 percent of Inglewood's residents had earned a bachelor's degree or higher (versus 27 percent across the country).

Twenty-nine percent of the city's population were foreign-born, compared to 13 percent in the nation as a whole.

In 2009, the Los Angeles Times's "Mapping L.A." project supplied these neighborhood statistics based on the 2000 census.

The population was 112,482, or 12,330 people per square mile, among the highest densities for the South Bay and among the highest densities for the county. The percentage of African Americans was high for the county, and the population was moderately diverse. Median household income was $46,574, low for both the South Bay and for the county. The median age was 29, young for the county; the percentage of residents aged 10 or under was among the county's highest. Three people, on the average, lived in each household – high for the South Bay but about average for the county. There was a higher percentage of families headed by single parents than elsewhere in the county. The percentage of veterans who served during 1975–89 and 1990–99 was among the county's highest.

(*) "The diversity index measures the probability that any two residents, chosen at random, would be of different ethnicities. If all residents are of the same ethnic group it's zero. If half are from one group and half from another it's .50."