Downstate Illinois refers to all of Illinois

Illinois

Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...

 outside of the Chicago metropolitan area. This term is flexible, but because it is generally meant to refer to everything outside the Chicago-area, some cities in Northern Illinois

Northern Illinois

Northern Illinois is a region generally covering the northern third of the U.S. state of Illinois.-Economics:Northern Illinois is dominated by the metropolitan areas of Chicago, Rockford, and the Quad Cities, which contain a majority of Illinois' population and economic activity, including...

, such as Rockford and DeKalb

DeKalb, Illinois

DeKalb is a city in DeKalb County, Illinois, United States. The population was 43,862 at the 2010 census, up from 39,018 at the 2000 census. The city is named after decorated German war hero Johann De Kalb, who died during the American Revolutionary War....

, (which are north and west of Chicago, respectively), are considered to be "downstate".

The term has been part of the Illinois vernacular

Vernacular

A vernacular is the native language or native dialect of a specific population, as opposed to a language of wider communication that is not native to the population, such as a national language or lingua franca.- Etymology :The term is not a recent one...

 for decades, and is commonly used by the media. The General Assembly

Illinois General Assembly

The Illinois General Assembly is the state legislature of the U.S. state of Illinois and comprises the Illinois House of Representatives and the Illinois Senate. The General Assembly was created by the first state constitution adopted in 1818. Illinois has 59 legislative districts, with two...

 (the state legislature

State legislature

In the United States of America, a state legislature is a generic term referring to the legislative body of any of the country's 50 states. The formal name varies from state to state. In 24 states, the legislature is simply called the "Legislature", or the "State Legislature", while in 19 states,...

 for Illinois) regularly makes references to the term in the titles of bills it passes.

Major Cities

Ten Largest Downstate Cities
Rank	City	Population	County
1	Rockford	157,280	Winnebago Winnebago County, Illinois Winnebago County is a county located in the U.S. state of Illinois. According to the 2010 census, it has a population of 295,266, which is an increase of 6.1% from 278,418 in 2000...
2	Springfield Springfield, Illinois Springfield is the third and current capital of the US state of Illinois and the county seat of Sangamon County with a population of 117,400 , making it the sixth most populated city in the state and the second most populated Illinois city outside of the Chicago Metropolitan Area...	118,033	Sangamon Sangamon County, Illinois Sangamon County is a county located in the U.S. state of Illinois. According to the 2010 census, it has a population of 197,465, which is an increase of 4.5% from 188,951 in 2000...
3	Peoria Peoria, Illinois Peoria is the largest city on the Illinois River and the county seat of Peoria County, Illinois, in the United States. It is named after the Peoria tribe. As of the 2010 census, the city was the seventh-most populated in Illinois, with a population of 115,007, and is the third-most populated...	115,520	Peoria Peoria County, Illinois Peoria County is a county located in the U.S. state of Illinois. According to the 2010 census, it has a population of 186,494, which is an increase of 1.7% from 183,433 in 2000. Its county seat is Peoria....
4	Champaign Champaign, Illinois Champaign is a city in Champaign County, Illinois, in the United States. The city is located south of Chicago, west of Indianapolis, Indiana, and 178 miles northeast of St. Louis, Missouri. Though surrounded by farm communities, Champaign is notable for sharing the campus of the University of...	80,286	Champaign Champaign County, Illinois Champaign County is a county located in the U.S. state of Illinois. According to the 2010 census, it has a population of 201,081, which is an increase of 11.9% from 179,669 in 2000.. It is the 10th most populous county in Illinois...
5	Decatur Decatur, Illinois Decatur is the largest city and the county seat of Macon County in the U.S. state of Illinois. The city, sometimes called "the Soybean Capital of the World", was founded in 1823 and is located along the Sangamon River and Lake Decatur in Central Illinois. In 2000 the city population was 81,500,...	76,199	Macon
6	Bloomington Bloomington, Illinois Bloomington is a city in McLean County, Illinois, United States and the county seat. It is adjacent to Normal, Illinois, and is the more populous of the two principal municipalities of the Bloomington-Normal metropolitan area...	74,184	McLean McLean County, Illinois McLean County is a county in the U.S. state of Illinois. McLean County is included in the Bloomington–Normal, Illinois Metropolitan Statistical Area. According to the 2010 census, it has a population of 169,572, which is an increase of 12.7% from 150,433 in 2000. Its county seat is...
7	Normal Normal, Illinois Normal is an incorporated town in McLean County, Illinois, United States. It had a population of 52,497 as of the 2010 census. Normal is the smaller of two principal municipalities of the Bloomington-Normal metropolitan area...	52,799	McLean McLean County, Illinois McLean County is a county in the U.S. state of Illinois. McLean County is included in the Bloomington–Normal, Illinois Metropolitan Statistical Area. According to the 2010 census, it has a population of 169,572, which is an increase of 12.7% from 150,433 in 2000. Its county seat is...
8	DeKalb DeKalb, Illinois DeKalb is a city in DeKalb County, Illinois, United States. The population was 43,862 at the 2010 census, up from 39,018 at the 2000 census. The city is named after decorated German war hero Johann De Kalb, who died during the American Revolutionary War....	43,862	DeKalb DeKalb, Illinois DeKalb is a city in DeKalb County, Illinois, United States. The population was 43,862 at the 2010 census, up from 39,018 at the 2000 census. The city is named after decorated German war hero Johann De Kalb, who died during the American Revolutionary War....
9	Moline Moline, Illinois Moline is a city located in Rock Island County, Illinois, United States, with a population of 45,792 in 2010. Moline is one of the Quad Cities, along with neighboring East Moline and Rock Island in Illinois and the cities of Davenport and Bettendorf in Iowa. The Quad Cities has a population of...	43,050	Rock Island Rock Island County, Illinois Rock Island County is a county located in the U.S. state of Illinois. According to the 2010 census, it has a population of 147,546, which is a decrease of 1.2% from 149,374 in 2000. Its county seat is Rock Island...
10	Belleville Belleville, Illinois Belleville is a city in St. Clair County, Illinois, United States. As of the 2010 census, the city has a population of 44,478. It is the eighth-most populated city outside of the Chicago Metropolitan Area and the most populated city south of Springfield in the state of Illinois. It is the county...	41,285	St. Clair St. Clair County, Illinois St. Clair County is a county located in the U.S. state of Illinois. In 1970, the U.S. Census Bureau placed the mean center of U.S. population in St. Clair County. According to the 2010 census, it has a population of 270,056, which is an increase of 5.5% from 256,082 in 2000. Its county seat is...

Most of the state's largest cities (six of the top ten) are concentrated in and around the Chicago , but several mid-sized cities exist in the downstate area as well. Rockford is the region's largest.