Chicago is the most populous city in the U.S. state of Illinois and the third-most populous in the United States, after New York City and Los Angeles. With a population of 2,746,388 in the 2020 census,[5] it is also the most populous city in the Midwest. As the seat of Cook County (the second-most populous U.S. county), the city is the center of the Chicago metropolitan area, one of the largest in the world.
