- Marina, Saint1
- Maritime1
- Mark, Saint1
- Marriage (Roman law)1
- Marriage--Moral and ethical aspects1
- Mary, Blessed Virgin, Saint, in the liturgy1
- Mary, Blessed Virgin, Saint, in the liturgy--Orthodox Eastern Church1
- Masses1
- Masses, Unaccompanied1
- Mathematics, Greek1
- Maximian, Emperor of Rome, approximately 240-3101
- Maximus, of Turin, Saint, active 4th century-5th century1
- Maḥzor. Yom Kippur1
- Medallions (Decorative arts)1
- Medici, Bernardo d'Alamanno de'1
- Medici, House of1
- Medici, Lorenzo de', 1449-14921
- Medicine, Ancient1
- Medicine, Magic, mystic, and spagiric1
- Mehmed II, Sultan of the Turks, 1432-14811