The 2006 Illinois High School Association (IHSA) State Championship Tournaments ended the twentieth State Championship Series conducted in Scholastic Bowl by the IHSA. It was the fifteenth season in which there were separate State Championship Tournaments held for small schools (Class A) and large schools (Class AA). For the tenth year, both tournaments were held at the Peoria Civic Center.
Teams were assigned to one of eight sectionals within each class. Teams were seeded by the coaches, and teams would then be assigned to one of four Regionals within each Sectional. The winners of the regionals would advance to their respective sectional tournaments, where they would play a three match round robin to determine a winner. The determination of the geographic boundaries of the Sectional was arbitrarily decided by the IHSA Office.
Each round was comprised of 30 toss-ups and accompanying bonus questions.
In the State Championship Tournament, teams would be randomly assigned to pools of four, and play a three match round robin. The winners of each pool would advance to the Championship Match, and the runners-up in each pool would advance to play for third place. Ties were broken by head-to-head results or total points scored (in the event of a three way tie)
The top four teams earned trophies and medals for team members, coaches, principals, and activities directors. The trophies were of the design smaller than that of the athletic trophies given out by the IHSA.
For the sixth year, the questions were written by a group of retired coaches and person from other states.
Latin School swept through their pool with a 3-0 record. Winnebago went 2-1, with a narrow loss to Latin, to advance to the third place match.
Both Decatur Lutheran and Illinois Valley Central went 2-1. IVC's victory in round one advanced them to the State Championship Match, and relegated Decatur Lutheran to the third place match.
Carbondale swept the pool (3-0) to advance to the Championship Match. Wheaton North went 2-1 and advance to play for third place.
Fremd swept the pool (3-0) to advance to the Championship Match. Auburn went 2-1 and advance to play for third place.
- The match between Winnebago and The Latin School was considered by most to be the true Class A State Championship match. The match saw Latin lead most of the way with Winnebago always keeping the match close. Brad Fischer was the leading scorer for the match, even though his Winnebago team had to settle for third place.
- A year after a loss to Stevenson in the Sectionals, Fremd was able to complete their quest for an IHSA State Championship.
- The Latin School placed in the top four for the fifth straight year, breaking their own Class A record of four consecutive years.
- This was the first Class AA State Championship Match since 2001 not to feature Wheaton North.
- Aside from IMSA, Stevenson. and Wheaton North, Fremd was the first new state champion since 1995.