Central Suburban League

The Central Suburban League is an IHSA-recognized high school extracurricular conference comprising 12 public schools located in the North Shore suburbs of Chicago. Comprising 12 relatively large high schools, it is among the larger high school conferences (by student population) in Illinois.

While the divisions' names are geographic, their makeup is not based on a school's location. The North Division includes the schools with the smaller enrollments while the South Division includes the schools with the larger enrollments. Every two years the member school's official enrollment is used to determine division alignment.

Not all activities and sports make use of the division alignment. In chess, teams compete as a part of the North Suburban Chess League which comprises schools from many conferences. Scholastic Bowl plays as a single twelve team league.

Niles North moved to the CSL South for the 2016-'17 season after former South Division school Waukegan was replaced with Vernon Hills. Vernon Hills, which had the smallest enrollment in the conference at that point, was placed in the North Division.

The CSL traces its history back to the founding of the Suburban League in 1913, of which Evanston and New Trier were both founding members. The league had somewhat fluid membership over several decades. As the population of suburban Chicago grew (and the number of high schools with it) schools began leaving to join newer conferences such as the West Suburban Conference (started 1922), the Northwest Suburban (started in 1925, which later became the North Suburban Conference and Mid-Suburban League), and the South Suburban League (started in 1950). With more schools leaving (and newer suburban schools joining more geographically logical conferences), the Central Suburban League was founded in 1965, the last major conference to be carved from the old Suburban League. The last remaining bastion of the Suburban League started joining these other leagues, and finally folded after the 1973–1974 school year.

As of the end of the 2007–08 school year, the past and present schools of the CSL have won 233 state titles in various IHSA sports and activities. They have finished in second place 261 times. Nearly half of these (105 state titles and 113 state runners-up) have been won by New Trier (or the two schools it was split into for a time, New Trier East and New Trier West). Evanston adds 47 state titles and 49 runner-up prizes. The league has remained stable (except for divisional realignment) since Niles North returned to the league in 1991.

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