| School | District | County |
|---|---|---|
| Mary Paxton Keeley | Columbia 93 | Boone |
| Maryville Middle | Maryville R-Ii | Nodaway |
| Mason | Lee s Summit R-Vii | Jackson |
| Mason | St. Louis City | St Louis City |
| Mason Ridge | Parkway C-2 | St Louis |
| Mathews | Nixa R-Ii | Christian |
| Mathis | Hayti R-Ii | Pemiscot |
| Matthews | Grain Valley R-V | Jackson |
| Matthews | New Madrid Co. R-I | New Madrid |
| Matthews | Sikeston R-Vi | Scott |
| May Greene | Cape Girardeau 63 | Cape Girardeau |
| Maysville | Maysville R-I | DeKalb |
| McBride | Springfield R-Xii | Greene |
| McCoy | Kansas City 33 | Jackson |
| McCurdy | Hazelwood | St Louis |
| McEowen | Harrisonville R-Ix | Cass |
| McGrath | Brentwood | St Louis |
| McGregor | Springfield R-Xii | Greene |
| McIntire | Fulton 58 | Callaway |
| McKelvey | Parkway C-2 | St Louis |
| McKinley | Joplin R-Viii | Jasper |
| McKinley | Normandy | St Louis |
| McMillan | Mexico 59 | Audrain |
| McNair | Hazelwood | St Louis |
| Meadow Heights | Meadow Heights R-Ii | Bollinger |
| Meadow Lane | Lee s Summit R-Vii | Jackson |
| Meadowbrook | North Kansas City 74 | Clay |
| Meadowmere | Grandview C-4 | Jackson |
| Meadows | Riverview Gardens | St Louis |
| Meadville | Meadville R-Iv | Linn |
| Memorial Middle | Joplin R-Viii | Jasper |
| Meramec | Clayton | St Louis |
| Meramec | St. Louis City | St Louis City |
| Meramec Heights | Fox C-6 | Jefferson |
| Meservey | Kansas City 33 | Jackson |
| Mesnier | Affton 101 | St Louis |
| Miami | Miami R-I | Bates |
| Miami | Miami R-I | Saline |
| Mid Rivers | Ft. Zumwalt R-Ii | St Charles |
| Mid-Buchanan | Mid-Buchanan Co. R-V | Buchanan |
| Middle | Neosho R-V | Newton |
| Middle Grove | Middle Grove C-1 | Monroe |
| Middletown | Wellsville Middletown R-I | Montgomery |
| Midway | Midway R-I | Cass |
| Midway Heights | Columbia 93 | Boone |
| Milan | Milan C-2 | Sullivan |
| Milan Middle | Milan C-2 | Sullivan |
| Mill Creek | Columbia 93 | Boone |
| Mill Creek | Independence 30 | Jackson |
| Mill Creek Upper | Belton 124 | Cass |