As of 2018 - 2022, the Chicago metropolitan area had the fourth highest foreign-born population in the United States, surpassed only by New York, Los Angeles, and Miami.

[16] According to the Brookings Institution, Chicago is one of only four US metropolitan areas to be considered "major-continuous gateways" for immigration from the early 20th century until present-day.

Along with New York, Boston, and San Francisco, the Chicago area's foreign-born proportion has exceeded the national average for every decade of the past century, suggesting its historic and continued desirability as a destination for new arrivals to the US.

[18][19] As early as the 1990s, however, observers noted that the suburbs began absorbing a larger amount of immigrants than the central city, which traditionally served as the funnel through which new arrivals entered.

[21] The Chicago metropolitan area has the third largest African American population, behind only New York City and Atlanta.

The main ethnic groups in Chicago include Irish, German, Italian, Mexican, Assyrian, Arab, Bangladeshi, Jews, English, Bosnian, Croatian, Bulgarian, Czech, Greek, Black, Korean, Chinese, Indian, Filipino, Lithuanian, Macedonian, Montenegrin, Albanian, Pakistani, Polish, Hungarian, Romanian, Russian, Serbian, Slovak, Swedish, Ukrainian, Dutch, Belgian, Cuban, Vietnamese, and Puerto Rican.

The Irish were able to assert themselves in politics due to their large population but also the fact that they knew English and that – thanks to the geographic position of Ireland on the periphery of Europe – they did not have ancestral ethnic rivalries.

"[22] The Irish gained entry to Chicago's Fire and Police Departments and have kept family traditions of participation in these units.

Germans have constituted a major portion of ethnic whites in Chicago since the beginning of the city's history.

When the Great Plains opened up for settlement in the 1830s and 1840s, many German immigrants stopped in Chicago to earn additional money before moving West to claim a homestead.

Although their numbers dropped because of reduced emigration from Germany and because World War I had made it unpopular to acknowledge one's German heritage, 22 percent of Chicago's population still did so in 1920.

They largely clustered in Jefferson Park on the city's Northwest Side, coming to the area mostly between the years 1907–1920.

By 1930 450 families of Volga German heritage were living in the Jefferson Park area, most of whom originated from Wiesenseite.

The Taste of Polonia Festival in Jefferson Park celebrates Polish culture annually on Labor Day weekend.

[29] Chicago has the third largest Italian American population in the United States, behind only New York City and Philadelphia.

Chicago's Italian community has historically been based along the Taylor Street and Grand Avenue corridors on the West Side of the city.

[25] [36] Chicago has the third-largest South Asian population in the United States, especially many Indians, Bangladeshi and Pakistanis.

As of the 2010 Census, Chicago has the third-largest Puerto Rican population in the continental United States,[37] after New York City and Philadelphia, and the fourth largest Mexican population in the United States after Los Angeles, San Antonio, and Houston.

Chicago is the center of the Palestinian and Jordanian immigrant communities in the United States,[39][40] and additionally has a large Assyrian population.

The Roma first came to Chicago during the large waves of Southern and Eastern European immigration to the United States in the 1880s until World War I.

[41] The first Bosnians settled in Chicago in the late 19th and early 20th centuries, joining other immigrants seeking better opportunities and better lives.

As the former Yugoslavia continued to find its identity as a nation over the last century, the people of Bosnia and Herzegovina sought stability and new beginnings in the city of Chicago many intending to return to their homeland.

In 1906, they established Dzemijetul Hajrije (The Benevolent Society) of Illinois to preserve the community's religious and national traditions as well as to provide mutual assistance for funerals and illness.

[52][53] The Chicago metropolitan area also includes adherents of Islam, Buddhism, Hinduism, Jainism, Sikhism, and the Baháʼí Faith, among others.