List of Illinois High School Association member conferences

The following is a list of Illinois High School Association member conferences. Schools that belong to these conferences compete with each other on a local level in athletics and non-athletic activities. As of the 2023-24 school year, there are 70 conferences within the IHSA.

Current Conferences

 * Apollo Conference
 * Big Northern Conference
 * Big Twelve Conference
 * Black Diamond Conference
 * Cahokia Conference (contains three divisions)
 * Central Illinois Conference
 * Central State Eight Conference
 * Central Suburban League (contains two divisions)
 * Chicago Catholic League (contains two divisions)
 * Chicago Prep Conference
 * Chicago Public High School League (contains ten divisions)
 * Chicagoland Christian Conference
 * DuKane Conference
 * DuPage Valley Conference
 * East Central Illinois Conference
 * East Suburban Catholic Conference
 * Egyptian Illini Conference
 * Fox Valley Conference
 * Gateway Metro Conference
 * Girls Catholic Athletic Conference
 * Greater Egyptian Conference
 * Heart of Illinois Conference
 * Illini Prairie Conference
 * Illinois Central Eight Conference
 * Independent School League
 * Inter County Athletic Conference
 * Interstate Eight Conference
 * Kishwaukee River Conference
 * Lake Shore Athletic Conference
 * Lincoln Prairie Conference
 * Lincoln Trail Conference
 * Little Illini Conference
 * Little Okaw Valley Conference
 * Little Ten Conference
 * Metro Suburban Conference
 * Metropolitan Prep Conference
 * Mid-Illini Conference
 * Midland Trail Conference
 * Mid-Suburban League (contains two divisions)
 * Mississippi Valley Conference
 * MSM Conference
 * National Trail Conference
 * Noble Athletic Conference
 * North Suburban Conference
 * Northeastern Athletic Conference
 * Northern Illinois Conference (NIC-10)
 * Northern Lake County Conference
 * Northwest Upstate Illini Conference (contains two divisions)
 * Pike County Conference
 * Prairieland Conference
 * River Valley Conference
 * Sangamo Conference
 * South Central Conference (Illinois)
 * South Egyptian Conference
 * South Seven Conference
 * South Suburban Conference
 * Southern Illinois River-to-River Conference (with Mississippi and Ohio River divisions)
 * Southland Athletic Conference
 * Southwest Prairie Conference
 * Southwest Suburban Conference
 * Southwestern Conference
 * Three Rivers Conference
 * Tomahawk Conference (Illinois)
 * Tri-County Conference
 * Upstate Eight Conference
 * Vermilion Valley Conference
 * West Central Conference
 * West Suburban Conference (contains two divisions)
 * Western Big 6 Conference
 * Western Illinois Valley Conference (contains two divisions)

Former conferences

 * Ambraw Valley Conference (1945-1955)
 * Big 8 (1980-1995)
 * Big Rivers Conference (football-only) (1999-2012)
 * Bi-County Conference (1917-1919)
 * Bi-County Conference (1970s-1998)
 * Blackhawk Conference (West) (1934-1990)
 * Blackhawk Conference (North) (1947-1972)
 * Bureau Valley Conference (1970s-1990s)
 * Capitol Conference (1964-1982)
 * Cenois Conference (1963-1969)
 * Central Conference (1956-1958)
 * Central Egyptian Conference (1929-1940)
 * Chicagoland Prep Conference (1961-1969)
 * Coal Belt Conference (1946-1956)
 * Cook County High School League (1889–1913)
 * Corn Belt Conference (1950–2017)
 * Des Plaines Valley Conference (1963-1985)
 * East Okaw Conference (1981-1995)
 * Eastern Illinois Conference (1952-1969)
 * Four Rivers Conference (2000-2006)
 * Fox Valley Conference (1952-1966)
 * Gateway East Conference (1979-1983)
 * Greater Midwestern Conference (1983-1986)
 * Heartland Conference (Illinois) (1978-1982)
 * Heart of Illinois Conference (1970s) (1972–1978)
 * Illini Central Conference (1985-1998)
 * Illini 8 Conference (1966-1981)
 * Illini Valley Conference (North Central) (1970-1972)
 * Illini Valley Conference (South Central) (1928-1973)
 * Illio Conference (1952-1975)
 * Illowa Conference (1952-1974)
 * Indian Valley Conference (1976-1994)
 * Iroquois Conference (1970s-1980s)
 * Kane County Conference (????-1917)
 * Kankakee Valley Conference (1950-1979)
 * La Moine Valley Conference (1952-1967)
 * Little 6 Conference (1952–1975)
 * Little 7 Conference (1921–1995)
 * Little 8 Conference (North Central) (1921–1975)
 * Little 8 Conference (Far North) (1920s–1980)
 * Little 8 Conference (Northeast) (1919–19??)
 * Little 8 Conference (Northwest) (1918–192?)
 * Little 8 Conference (Southwest) (????–????)
 * Little Egypt Conference (1960s-1970s)
 * Little Five Conference (1923-1939)
 * Little Four Conference (19??'s-1948)
 * Meridian Conference (Central Illinois) (1959-1993)
 * Meridian Conference (Northern Illinois) (????-????)
 * Metro Catholic Conference (1960-1965)
 * Mid Northern Confernce (1972-1995)
 * Mid-South Conference (1983-2008)
 * Mid-State Conference (1944-1997)
 * Mid-State Six Conference (196?-2015)
 * Midwest Conference (1948-1970)
 * Midwestern Conference (1952-1970)
 * Mississippi Valley Conference (1957-1968)
 * New Salem Conference
 * North Central Illinois Conference (1929-2011)
 * North Egypt Conference (1938-2003)
 * North Shore Conference (1904-1914)
 * North Six Conference (1939-1946)
 * Northern Illinois Big 12 Conference (2010-2018)
 * Northwest Conference (1963-1974)
 * Northwest Illinois Conference (NWIC) (1974-1996)
 * Northwest 7 Conference (1972-1973)
 * Northwest 8 Conference (1977-1990)
 * Northwest Suburban Conference (1925-1997)
 * Okaw Valley Conference (1950s-2017)
 * Olympic Conference (1976-2010)
 * PMSC Conference (1961-1973)
 * Prairie State Conference (1985-????)
 * Quad Cities Metro Conference (1950-1977)
 * River Trails Conference (1990-1995)
 * Rock River (Valley) Conference (1924-1948)
 * Route 72 Conference (1952-1972)
 * Sangamon Valley Conference (1948-2021)
 * SHARK Conference (1946-1982)
 * SICA — (South Inter-Conference Association, dissolved 2006)
 * Southeast Suburban Conference (1962-1972)
 * Southern Conference (IHSA) (????-????)
 * Southern Illini Conference (1957-1974)
 * Southern Illini Conference (1986-1993)
 * Southwest Egyptian Conference (????-1993)
 * Spoon River Conference (1959-1985)
 * Stephenson County Conference (1958-1963) (Renamed "Northwest Illinois Conference")
 * Suburban Catholic Conference (1960-1973)
 * Suburban Catholic Conference (2009-2015)
 * Suburban League (1913–1975)
 * Suburban Prairie Conference (1995-2005)
 * SWANI Conference (1946-1953)
 * Tollway Athletic Conference
 * Trailblazer Conference (1982-1984)
 * Tri State Conference (1932-1935)
 * Two Rivers Conference (19??-1958)
 * United Conference (1958-1963)
 * Upstate Illini Conference (1974-1976)
 * Upstate Illini Conference (1991-2000)
 * US Grant Conference (1950-1958)
 * Vermilion Valley Conference (1950-1981)
 * Wauseca Conference (1928-1989)
 * West Prairie Trail Conference
 * Western Area Conference (1974-1996)
 * Western Athletic Conference (1908-1921)
 * Western Sun Conference (2006-2010)
 * Western Suburban Athletic Conference (1903-1910)
 * Western Suburban Catholic Conference (1974-1988)
 * Wilco Conference (1959-1973)
 * Wil-Ro-Kee Conference (1954-1959) (Renamed "Kankakee Valley Conference" in 1960)