| Composer | Title | Year | Pages & duration |
| Maclean, Clare (1958-) | How brightly shines the morning star: Processional and concert piece | 1985 | 12p. |
| Mageau, Mary J. (1934 -) | Unknown work(s) | ||
| Mallinson, Albert | O danke nicht | 1898 | |
| Massey, Joseph (1854-1943) | The three doves (Fantasy on a Christmas carol) | ||
| Mathias, Philip | Festival Prelude on "Ein' feste Burg" | 1999? | |
| Mayer, Gregory (1969-) | Pastorale and fugue | 1994 | 9p. |
| McCaughey, John | Wedding music 73 | 1973 | |
| Intendomi chi puo che m'intend'io for organ & tape (for Douglas Lawrence) | 1976 | ||
| McIver, Ronald (1913-) | Introduction and allegro | 1989 | 9p. 4m. |
| McKie, William (1901-1984) | Romance in g minor (published as B flat) | 1931 | 3p. 4m. |
| McKimm, Barry (1941-) | Sonata for trumpet and organ originally for trumpet & orchestra | 1976/1988 | 30p. 11m. |
| McRoberts, Nicholas (1977-) |
Festival fanfare for St John's Lutheran Church, Southgate for organ, tympani, triangle, tubular bells & suspended cymbal; commissioned by SJS. | 1997 | 4p. 3m. |
| Meale, Richard (1932-) | The Maids: Incidental music for electric organ | 1965 | |
| Mills, Richard (1949-) |
Hymnus and contrapunctus for organ & brass choir of four trumpets, three trombones, tuba (requested withdrawn) | 1971 | 89p. 20m. |
| Two pieces for organ | 1973 | ||
| Epithalamium | 1985 | 7p. 4m. | |
| Monkton, Edward | Ode in d minor | 1968 | |
| Moreno, Stephen (1889-1954) | Gregorian manual | ||
| Morgan, Derek (1915-) | Concert piece (with string orchestra, string quartet, solo trumpet, brass & percussion) | 39p. 11m. | |
| Morgan, David S. (1932-) | Plainsong prelude | 1954 | |
| Mote, Arnold R. (1880-c. 1950) | Gavotte Op. 13 | 1905 | |
| Serenade from The Shires suite Op. 35 no. 1 | c. 1905 | ||
| Solemn march in C | c. 1906 | ||
| Christmas fantasia on a theme of Mendelssohn Op. 43 | c. 1906 | ||
| Voluntary on "Eventide" | 1908 | ||
| Fantasia | c. 1908 | ||
| Munro, Gordon |
Suite for organ Toccata Hocket Chant Meditation Crystallisation |
1999 |
|
| Muset, Joseph (1889-1957) (Muset-Ferrer) | Litany for organ: 14 works from the Litany of Loreto; published with assistance of Archbishop Mannix, dedicated to Percy Jones | 1931-1943 | 134p. |