The M8 was formed in 2004 with eight charter members: Becker, Big Lake, Buffalo, Cambridge-Isanti, Monticello, Princeton, Rogers and St. Michael-Albertville (STMA), and began play in the 2005-2006 school year. Zimmerman High School was added to the conference in 2008.
Elk River High School entered the M8 as a competitor in the sport of football in 2010 and Duluth East and Duluth Denfeld High Schools joined the conference for football in the fall of 2012. St. Francis, Chisago Lakes Area, and North Branch Area High School began competing in the Mississippi 8 Conference during 2013-14 school year. Princeton School District and Zimmerman High School voted to withdraw their participation from the Mississippi 8 in favor of a new conference,
Granite Ridge Conference, for the 2011 school year. Becker School District, and Elk River High School left the conference in 2012, Becker joined the Granite Ridge Conference, and Elk River High School football rejoined the
Northwest Suburban Conference. In the 2013-14 school year, Princeton rejoined the M8. In 2018 STMA and Buffalo decided to leave the conference and were placed in the
Lake Conference by the MSHSL and Rogers decided to leave for the Northwest Suburban Conference beginning in the Fall of 2019. Becker High School rejoined the conference in 2019 bringing the total number of schools back to 8. ==Members==