The Southwest Prairie Conference (SPC) is an athletic and competitive activity conference consisting of twelve public high schools in Northern Illinois.
All but Romeoville and Plainfield North made up the South Division of the Suburban Prairie Conference.
Morris left the SPC following the 2008–09 school year to join the North Central Illinois Conference.
Newly established Plainfield East High School would replace them.
[1] Joliet Central and Joliet West High Schools joined the conference from the Southwest Suburban Conference at the start of the 2016–2017 school year, following a 2014 decision.