quality:corruption, structural:expansion, structural:reformatting, linguistic:translation
2020 census

At the 2010 census, there were 305,704 people residing in Pittsburgh, a decrease of 8.6% since 2000; 66.0% of the population was White, 25.8% Black or African American, 0.2% American Indian and Alaska Native, 4.4% Asian, 0.3% Other, and 2.3% mixed; in 2020, 2.3% of Pittsburgh's population was of Hispanic or Latino American origin of any race. Non-Hispanic whites were 64.8% of the population in 2010, compared to 78.7% in 1970. By the 2020 census, the population slightly declined further to 302,971. Its racial and ethnic makeup in 2020 was 64.7% non-Hispanic white, 23.0% Black or African American, 5.8% Asian, and 3.2% Hispanic or Latino American of any race.

Since the beginning of the 21st century, the five largest European ethnic groups in Pittsburgh were German (19.7%), Irish (15.8%), Italian (11.8%), Polish (8.4%), and English (4.6%), while the metropolitan area is approximately 22% German-American, 15.4% Italian American and 11.6% Irish American. Pittsburgh has one of the largest Italian-American communities in the nation, and the fifth-largest Ukrainian community per the 1990 census. Pittsburgh has one of the most extensive Croatian communities in the United States. Overall, the Pittsburgh metro area has one of the largest populations of Slavic Americans in the country.

Pittsburgh has a sizable Black and African American population, concentrated in various neighborhoods especially in the East End. There is also a small Asian community consisting of Indian immigrants, and a small Hispanic community consisting of Mexicans and Puerto Ricans.

According to a 2010 Association of Religion Data Archives (ARDA) study, residents include 773,341 "Catholics"; 326,125 "Mainline Protestants"; 174,119 "Evangelical Protestants;" 20,976 "Black Protestants;" and 16,405 "Orthodox Christians," with 996,826 listed as "unclaimed" and 16,405 as "other" in the metro area. A 2017 study by the Cohen Center for Modern Jewish Studies at Brandeis University estimated the Jewish population of Greater Pittsburgh was 49,200. Pittsburgh is also cited as the location where the earliest precursor to Jehovah's Witnesses was founded by Charles Taze Russell; today the denomination makes up approximately 1% of the population based on data from the Pew Research Center.

According to a 2014 study by the Pew Research Center, 78% of the population of the city identified themselves as Christians, with 42% professing attendance at a variety of churches that could be considered Protestant, and 32% professing Catholic beliefs. while 18% claim no religious affiliation. The same study says that other religions (including Judaism, Buddhism, Islam, and Hinduism) collectively make up about 4% of the population.

In 2010, there were 143,739 households, out of which 21.9% had children under the age of 18 living with them, 31.2% were married couples living together, 16.5% had a female householder with no husband present, and 48.4% were non-families. 39.4% of all households were made up of individuals, and 13.7% had someone living alone who was 65 years of age or older. The average household size was 2.17 and the average family size was 2.95.

In the city, the population was spread out, with 19.9% under the age of 18, 14.8% from 18 to 24, 28.6% from 25 to 44, 20.3% from 45 to 64, and 16.4% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 90.7 males. For every 100 females age 18 and over, there were 87.8 males.

The median income for a household in the city was $28,588, and the median income for a family was $38,795. Males had a median income of $32,128 versus $25,500 for females. The per capita income for the city was $18,816. About 15.0% of families and 20.4% of the population were below the poverty line, including 27.5% of those under the age of 18 and 13.5% ages 65 or older. By the 2019 American Community Survey, the median income for a household increased to $53,799. Families had a median income of $68,922; married-couple families had a median income of $93,500; and non-family households had a median income of $34,448. Pittsburgh's wealthiest suburbs within city limits are Squirrel Hill and Point Breeze, the only two areas of the city which have average household incomes over $100,000 a year. Outside of city limits, Sewickley Heights is by a wide margin the wealthiest suburb of Pittsburgh within Allegheny County, with an average yearly household income of just over $218,000. Sewickely Heights is seen as one of Pittsburgh's wealthiest suburbs culturally as well, titles which the suburbs of Upper St. Clair, Fox Chapel, Wexford, and Warrendale also have been bestowed.

In a 2002 study, Pittsburgh ranked 22nd of 69 urban places in the U.S. in the number of residents 25 years or older who had completed a bachelor's degree, at 31%. Pittsburgh ranked 15th of the 69 places in the number of residents 25 years or older who completed a high school degree, at 84.7%.

The metro area has shown greater residential racial integration during the last 30 years. The 2010 census ranked 18 other U.S. metros as having greater black-white segregation, while 32 other U.S. metros rank higher for black-white isolation.

As of 2018, much of Pittsburgh's population density was concentrated in the central, southern, and eastern areas. The city limits itself have a population density of 5,513 people per square mile; its most densely populated parts are North Oakland (at 21,200 per square mile) and Uptown Pittsburgh (at 19,869 per square mile). Outside of the city limits, Dormont and Mount Oliver are Pittsburgh's most densely-populated neighborhoods, with 11,167 and 9,902 people per square mile respectively.

Most of Pittsburgh's immigrants are from China, India, Korea and Italy.