The City of Chicago Math League is sponsored by the Chicago Board of Education to encourage high school students (grades 9-12 only) to challenge themselves mathematically. Each year, at least thirty schools compete over five contests (four "regular" contests plus a citywide finals) to determine the city champion and to prepare for competition at the state level.

Each contest consists of a 20 question exam which must be completed in 50 minutes. Contests are administered at three sites; schools are assigned to sites based on their locations. Competition is divided into four grade level/topic areas: Algebra 1 (9th grade), Geometry (10th grade), Algebra 2 (11th grade), and Pre-Calculus (12th grade). At each regional meet, ribbons are awarded to the top three students in each subject in Division A and in Division B/C. After four meets, the top 30 students in each category, based on city-wide rankings, are invited to the city finals. Seven awards are then given in each subject based on the results of the citywide finals.