The Mid-Suburban League (MSL) is an Illinois High School Association recognized high school extra-curricular league which includes 12 schools located in the northwest suburbs of Chicago, Illinois. The conference is split up into two divisions for all interscholastic activities. The primary criteria for the separate divisions is geography, with the schools in the West Division being located west of IL Route 53 and the schools of the East Division being east of it. However, the schools of the western division are also larger than the schools of the eastern division.

Prospect High School, or Prospect, is a public four-year high school in Mount Prospect, Illinois, United States. It is part of Township High School District 214, which also includes Buffalo Grove High School, Elk Grove High School, John Hersey High School, Rolling Meadows High School, and Wheeling High School. It serves central Mount Prospect and a large portion of east Arlington Heights close to the Mt. Prospect village limits. Its feeder schools are Lincoln Middle School, South Middle School, Friendship Junior High School and Holmes Junior High School.