- Martini, Luca, 1980-1
- Martyrologies1
- Martyrs1
- Mary Magdalene, Saint1
- Mary, Blessed Virgin, Saint, in the liturgy1
- Masses1
- Masses, Unaccompanied1
- Mathematical recreations1
- Mathematics, Greek1
- Maurice, Saint, -approximately 2871
- Maximian, Emperor of Rome, approximately 240-3101
- Maximilian I, Holy Roman Emperor, 1459-15191
- Mechanics1
- Medical astrology1
- Medici, Alessandro de', 1510-15371
- Medici, Bernardo d'Alamanno de'1
- Medici, Giuliano de', 1453-14781
- Medici, Lorenzo de', 1449-14921
- Medici, Piero di Lorenzo de', 1472-15031
- Medicine, Greek and Roman1