This is a list of sister cities in the United States state of Illinois. Sister cities, known in Europe as town twins, are cities which partner with each other to promote human contact and cultural links, although this partnering is not limited to cities and often includes counties, regions, states and other sub-national entities.
Many Illinois jurisdictions work with foreign cities through Sister Cities International, an organization whose goal is to "promote peace through mutual respect, understanding, and cooperation." [1]
DuPage County is a county in the U.S. state of Illinois, and one of the collar counties of the Chicago metropolitan area. As of the 2020 census, the population was 932,877, making it Illinois' second-most populous county. Its county seat is Wheaton.
Woodridge is a village in DuPage County, Illinois, with small portions in Will and Cook counties, and a southwestern suburb of Chicago. Per the 2020 census, the population was 34,158.
Bolingbrook is a village in Will and DuPage counties in the U.S. state of Illinois. It is a southwest suburb of Chicago on I-55 and Historic Route 66. The village was a new town built on the Gateway Wetlands west of the Des Plaines River in the 1960s. Bolingbrook experienced rapid growth in the 1980s and 1990s, eventually becoming Will county's second largest town after Joliet. Per the 2020 census, the population was 73,922. As of 2010, it is the 17th largest incorporated place in Illinois and the state's second-largest village.
Glen Ellyn is a village in DuPage County, Illinois, United States. A suburb located 24 miles (39 km) due west of downtown Chicago, the village has a population of 28,846 as of the 2020 Census.
Lombard is a village in DuPage County, Illinois, United States, and a suburb of Chicago. The population was 44,476 at the 2020 census.
Naperville is a city in DuPage and Will counties in the U.S. state of Illinois. It is a southwestern suburb of Chicago located 28 miles (45 km) west of the city on the DuPage River. As of the 2020 census, its population was 149,540, making it the state's fourth-most populous city.
Westmont is a village in DuPage County, Illinois, United States. Located in the southeastern portion of DuPage County, Westmont is a community of 5.03 square miles in area with a 2020 population of 24,429. It is a southwest suburb of Chicago.
Wheaton is a city in Milton and Winfield Townships and is the county seat of DuPage County, Illinois, United States. It is located approximately 25 miles (40 km) west of Chicago. As of the 2020 census, Wheaton's population was 53,970, making it the 27th most populous municipality in Illinois.
The DuPage River is a 28.3-mile-long (45.5 km) tributary of the Des Plaines River in the U.S. state of Illinois.
Area codes 630 and 331 are telephone area codes in the North American Numbering Plan (NANP) for portions of Chicago's near and far western suburbs, including the majority of DuPage County, Illinois. To the northwest, the numbering plan area (NPA) also includes a small portion of Cook County, including parts of Schaumburg, Streamwood and Hanover Park. To the west, Kane County is divided between area codes 847 and 224 in the north, including Elgin, and area codes 630 and 331 in the south, including Aurora. To the south, the northern part of Will County and a small part of southern Cook County, including the village of Burr Ridge and parts of the village of Lemont, are also included in the 630 and 331 area codes. To the southwest, the city of Yorkville, in exurban Kendall County, is included, as well.
The Upstate Eight Conference is an organization of ten high schools in northeastern Illinois, representing ten communities in Chicago's suburbs. These high schools are all members of the Illinois High School Association.
The Illinois Technology and Research Corridor is a region of commerce and industry located along Interstate 88 in the Chicago metropolitan area, primarily in Cook, DuPage, Kane, and DeKalb Counties. The corridor is home to the headquarters or regional centers for many Fortune 1000 companies, several office and industrial parks, colleges and universities, research and scientific institutions, medical centers, government centers, and abundant shopping, dining, lodging, and entertainment amenities. In addition to the I-90 Golden Corridor, the I-94 Lakeshore Corridor, and the I-55 Industrial Corridor, the Illinois Technology and Research Corridor is one of the principal economic centers in suburban Chicago.