The St Louis Suburban Public High School Athletic and Activities Association (SPHSAAA) is a high school extracurricular league located in the suburbs of St. Louis. There are 31 schools in the Suburban Conference, making it one of the largest high school athletic conferences in the state of Missouri. The conference comprises mostly schools in St. Louis County but also a handful from Jefferson County.  All schools are members of the Missouri State High School Activities Association (MSHSAA).

Because of the large number of teams in the conference, the conference was once divided geographically into sub-conferences, and divisions. Prior to the 2014-15 school year, there were four conferences – Suburban East, Suburban North, Suburban South, and Suburban West.

For the 2014-15 seasons, the conference was re-aligned into three sub-conferences, each with two divisions.

In 2018, the St. Louis Suburban Public High School Athletic and Activities Association re-aligned their three conferences into various pools by sport, essentially making the sub-conferences and divisions irrelevant, as a given school competes against a different pool of schools in various sports. For purposes of athletic competition, pool assignments are based on the following factors: athletics offered, competitive balance, competitive trends, diversity, and school size. The number of pools varies from two in sports like Cross Country and Boys’ Volleyball all the way to five in Basketball and Football.  The number of pools is determined by the number of schools that offer the sport(s), the number of games allowed, what best fits the conference for growth, and competitive balance