Southern Indiana Athletic Conference

The Southern Indiana Athletic Conference (SIAC) is a high school athletic conference based in Evansville, Indiana. Five of the conferences 10 schools; Bosse, Central, Harrison, North, and Reitz; comprise the public Evansville Vanderburgh School Corporation. Mater Dei and Memorial are private Catholic high schools run by the Roman Catholic Diocese of Evansville, and the largest member is Castle, a public school located in neighboring Newburgh in Warrick County under the Warrick County School Corporation. The league was founded in 1936, and at one point stretched far across southern and western Indiana: from Mount Vernon in the west to New Albany in the east, and from Evansville in the south to Terre Haute in the north. Jasper and Vincennes Lincoln announced in May 2019 that they would leave the disbanding Big Eight Conference to rejoin the Southern Indiana Athletic Conference beginning with the 2020–21 season.

Former members

 * 1) Linton played concurrently in the SIAC and West Central Conference 1944–45, and the SIAC and WIC 1945–51.
 * 2) Sullivan played in both the SIAC and West Central Conference 1944–45, and the SIAC and WIC 1945–62.

John H. Castle Knights

 * Football (1982, 1994)
 * Boys Soccer (2000)
 * Girls Basketball (2006)
 * Softball (2001)

Evansville Benjamin Bosse Bulldogs

 * Boys Basketball (1943, 1944, 1962)

Evansville Central Bears
None

Evansville William Henry Harrison Warriors

 * Girls Golf (1989)
 * Boys Golf (2012)

Evansville Mater Dei Wildcats

 * Baseball (1999)
 * Boys Basketball (2004)
 * Girls Basketball (2012, 2013)
 * Football (2001, 2022)
 * Wrestling (1986, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2006, 2007, 2021)
 * Softball (2016)
 * Girls Soccer (2017, 2018, 2019)

Evansville North Huskies

 * Baseball (1962*)
 * Boys Basketball (1967)
 * Boys Golf (2000)
 * Girls Golf (2014, 2015, 2016, 2018, 2020, 2021)

* = indicates title won before IHSAA State Tournament was initiated

Evansville Francis Joseph Reitz Panthers

 * Girls Basketball (1981)
 * Football (1933*, 1940*, 1948*, 1953*, 1956*, 1957*, 1960*, 1961*, 1971*, 2007, 2009)
 * Bowling (2012+)

* = indicates title won before IHSAA State Tournament was initiated

+ = indicates title sanctioned by the Indiana High School Bowling Association

Evansville Reitz Memorial Tigers

 * Baseball (1978, 1989, 1993)
 * Football (1937*, 1958*, 2017, 2019)
 * Girls Soccer (1989*, 1997, 2008, 2013, 2017, 2021, 2022)
 * Softball (2002)
 * Girls Tennis (1991, 1993, 1994, 1995, 1996, 2012)
 * Boys Soccer (1979*, 1980*, 1981*, 1983*, 1984*, 1986*, 1988*, 1989*, 1990*, 1992*, 2007, 2008, 2016, 2017, 2019, 2020)
 * Girls Basketball (2011)

* = indicates title won before IHSAA State Tournament was initiated

Jasper Wildcats

 * 1949 Boys' Basketball
 * 1996 Baseball
 * 1997 Baseball
 * 1998 Baseball (3A)
 * 1999 Boys' Tennis
 * 2000 Baseball (3A)
 * 2001 Football (4A)
 * 2006 Baseball (3A)
 * 2021 Baseball (4A)

Vincennes Lincoln Alices

 * 1923 Boys' Basketball
 * 1981 Boys' Basketball
 * 2002 Baseball (3A)

Neighboring conferences

 * Big Eight Conference
 * Pocket Athletic Conference