From 1981-2000, the contest was two divisions: A (750 or less students) and AA (751+ students)
| Division A | Division AA | |
|---|---|---|
| 1981 | Red Bud | New Trier East |
| 1982 | Sparta | New Trier |
| 1983 | Sparta | New Trier |
| 1984 | Sparta | New Trier |
| 1985 | Sparta | New Trier |
| 1986 | Oblong | New Trier |
| 1987 | Sparta | New Trier |
| 1988 | Sparta | New Trier |
| 1989 | Oblong | Evanston |
| 1990 | Johnston City | IL Math/Science Academy |
| 1991 | Oblong | Adlai E Stevenson |
| 1992 | Johnston City | IL Math/Science Adademy |
| 1993 | Sparta | IL Math/Science Academy |
| 1994 | Sparta | Naperville North |
| 1995 | Sparta | Naperville North |
| 1996 | Sparta | Naperville North |
| 1997 | Sparta | IL Math/Science Academy |
| 1998 | Sparta | Naperville North |
| 1999 | University of Chicago Lab | Naperville North |
| 2000 | Oblong | Naperville North |
In 2001, the contest moved to four divisions.
| Division 1A | Division 2A | Division 3AA | Division 4AA | |
|---|---|---|---|---|
| 2001 | Oblong | Vernon Hills | Glenbrook North | Naperville North |
| 2002 | Johnston City | University of Chicago Lab | Fenwick | Naperville North |
| 2003 | Johnston City | Herrin | Libertyville | Naperville North |
| 2004 | Johnston City | Walter Payton College Prep | Libertyville | Naperville North |
| 2005 | Johnston City | Walter Payton College Prep | Benet Academy | Naperville North |
| 2006 | Johnston City | Walter Payton College Prep | Glenbard South | Naperville North |
| 2007 | Cornerstone | University of Chicago Lab | Walter Payton College Prep | Naperville North |
| 2008 | Cornerstone | University of Chicago Lab | Vernon Hills | IL Math/Science Academy |
| 2009 | Cornerstone | University of Chicago Lab | Vernon Hills | IL Math/Science Academy |
| 2010 | Cornerstone | University of Chicago Lab | Walter Payton College Prep | IL Math/Science Academy |
| 2011 | Cornerstone | University of Chicago Lab | Walter Payton College Prep | Naperville North |
| 2012 | Cornerstone | Morton | Benet Academy | IL Math/Science Academy |
| 2013 | Cornerstone | University of Chicago Lab | Libertyville | Whitney Young |
| 2014 | Cornerstone | University of Chicago Lab | Vernon Hills | Whitney Young |
| 2015 | Cornerstone | University of Chicago Lab | Libertyville | Adlai E Stevenson |
| 2016 | Cornerstone | Mahomet-Seymour | Libertyville | Naperville North |
| 2017 | Cornerstone | Mahomet-Seymour | Glenbrook North | Naperville North |
| 2018 | Cornerstone | Lake Forest Academy | Glenbrook North | Naperville North |
| 2019 | Cornerstone | Mahomet-Seymour | Glenbrook North | Naperville North |
| 2020 | No State Finals | No State Finals | No State Finals | No State Finals |
| 2021 | No State Finals | No State Finals | No State Finals | No State Finals |
| 2022 | Cornerstone | Fenwick | University of Chicago Lab | Adlai Stevenson |
| 2023 | College Prep Sch of Am | Lake Forest Academy | University of Chicago Lab | Adlai Stevenson |