Chicago is the third most populous city in the United States. With over 2.7 million residents, it is the most populous city in the state of Illinois and the Midwest. The Chicago metropolitan area, often referred to as Chicagoland, is home to nearly 10 million people and is the third-largest in the U.S. Chicago is the seat of Cook County.
About this site
Welcome to the official City of Chicago Website. The source for information about City services, departments, programs and initiatives, and officials for Chicago residents, businesses, and visitors.