The following lists Missouri high schools and the athletic conferences in which they compete.
[1] Under the current system used by the Missouri State High School Activities Association some conference member teams may also compete in the same playoff district while others are in districts with non-conference members.
[12] [13] [14] (2024) [15] (2024) [16] [17] Two former members, Heritage Christian Academy (Olathe, KS) and Cair Paravel Latin (Topeka, KS) are now full members of the Kansas State High School Activities Association.
Excelsior Springs departed after the 2021-22 school year and followed Grain Valley to the Suburban Kansas City Conference.
Independents are included in the MSHSAA playoff system based on a District assignment separate from any athletic conference.