The DuPage Valley Conference (DVC) is an organization of six high schools in northeastern Illinois, representing seven communities in Chicago's suburbs. These high schools are all members of the Illinois High School Association. The Conference, organized in 1975, exists primarily for inter-school athletic competition in 21 sports. There are also four non-athletic competitions in which DVC schools participate: Chess, Math competitions, Scholastic Bowl and Speech.
The Upstate Eight Conference is an organization of fourteen 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 North Suburban Conference (NSC) is an extra-curricular conference of eight high schools located in Lake County, Illinois, in the northern suburbs of Chicago. All of the schools are members of the Illinois High School Association (IHSA).
The Big Northern Conference (BNC) is an organization of ten high schools in northern Illinois. These high schools are members of the Illinois High School Association.
The Three Rivers Conference, also known as the TRAC-8, is a high school conference in northwest Illinois. The conference participates in athletics and activities in the Illinois High School Association. The conference comprises small public, and two private, high schools with enrollments between 200-600 students in portions of Bureau, Henry, Lee, Rock Island, and Whiteside counties.
The Prairieland Conference is a high school athletic conference in western central Illinois. The conference participates in athletics and activities in the Illinois High School Association. The conference comprises small public high schools with enrollments between 50 and 400 students in portions of Fulton, Knox, Mason, McDonough, Peoria, Schuyler, and Warren counties.
The West Central Conference is a high school conference in western central Illinois. The conference participates in athletics and activities in the Illinois High School Association. The conference comprises 11 small public high schools and 1 private high school with enrollments between 120-590 students in Adams, Hancock, McDonough, Pike, and Warren counties.
The Northwest Upstate Illini Conference is a high school conference in northwest and north central Illinois. The conference participates in athletics and activities in the Illinois High School Association. The conference comprises 20 small public high schools and one small private school, with enrollments between 60-340 students in Carroll, Jo Daviess, Lee, Ogle, Stephenson, Whiteside, and Winnebago counties.
The Little 7 Conference was a high school athletic conference in Illinois. It was officially organized in October 1921 for 1921–1922 school year.
The Little Illini Conference is a high school athletic conference in East Central Illinois that is a member of the Illinois High School Association. A group of small schools near the Indiana border, Little Illini is known for its strong football squads, in particular Casey-Westfield, which has won one state football championship The conference has undergone significant rearrangement in the past decade with the addition of several larger schools from the Apollo Conference driving many smaller schools to other conferences.
The Okaw Valley Conference was a high school athletic conference in the Illinois High School Association (IHSA), based in Central Illinois. The conference consisted of medium-sized and small high schools. It merged with the Corn Belt Conference to form the Illini Prairie Conference in the 2017-18 school year.
The Big Rivers Conference of Illinois was a high school football-exclusive athletic conference that existed from the 1999 through the 2012 football season. Upon its dissolution, it comprised ten teams located in the northwest and north-central portions of the state. It was a member of the Illinois High School Association, and its sister conference for other sports was the Three Rivers Conference. As of the 2013-14 school year, in tandem with a conference expansion, Big Rivers has been reabsorbed into the Three Rivers Conference. This expansion negotiated full membership status for member schools in all Three Rivers Conference sports, thereby negating the need for a football conference carve-out.
The Upstate Illini Conference (UIC) was a high school conference in northwest and north central Illinois. The conference participated in athletics and activities in the Illinois High School Association. The conference included small public and private high schools with enrollments between 75-1,000 students in Bureau, Boone, Carroll, DeKalb, Jo Daviess, Kane, Lee, McHenry, Ogle, Stephenson and Winnebago counties.
The Corn Belt Conference was a high school athletic conference in the Illinois High School Association (IHSA), based in Central Illinois. The conference consisted of medium-sized and small high schools.
The Illini Prairie Conference is a high school athletic conference in the Illinois High School Association (IHSA), based in Central Illinois. The conference comprises ten medium-sized and small high schools resulting from the merging of the Corn Belt Conference and the Okaw Valley Conference. Conference athletics began in the 2017-18 school year.
The Northwest 8 Conference was a high school conference in northwest and north central Illinois. The conference participated in athletics and activities in the Illinois High School Association. The conference included small public high schools with enrollments between 75-600 students in Boone, Carroll, DeKalb, Jo Daviess, Lee, Ogle, Stephenson, and Winnebago counties.
The Four Rivers Conference was a high school conference in north central Illinois. The conference participated in athletics and activities in the Illinois High School Association. The conference included small public high schools with enrollments between 150-550 students in Boone, DeKalb, Lee and Winnebago counties. The conference was named for the 4 rivers that ran through its geographic area, the Rock River, Pecatonica River, Kishwaukee River and Sugar River.
The Northwestern Illinois Conference, known locally as the NWIC, was a high school conference in northwest and north central Illinois. The conference participated in athletics and activities in the Illinois High School Association. The conference included small public high schools, and one small private school, with enrollments between 75-400 students in Carroll, Jo Daviess, Stephenson and Winnebago counties.
The Lincoln Prairie Conference or LPC, is a high school athletic conference in Central Illinois. The first year of existence was the 2019-20 school year. Its schools belong to the IHSA and compete in many sports and other activities.
The Little Okaw Valley Conference is a high school conference in central Illinois, in the United States. The conference participates in athletics and activities in the Illinois High School Association. The conference comprises five small public high schools with enrollments between 80 and 270 students in Coles, Champaign, Douglas, Moultrie, and Piatt counties.