- Masses, Unaccompanied1
- Mathematical recreations1
- Mathematics, Greek1
- Mathematics, Jewish1
- Maurice, Saint, -approximately 2871
- Maximian, Emperor of Rome, approximately 240-3101
- Maximus, of Turin, Saint, active 4th century-5th century1
- Medallions (Decorative arts)1
- Medical care1
- 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, Ancient1
- Mediterranean Region1
- Mediterranean Sea--Adriatic Sea1
- Mensural notation1
- Mercenary troops1
- Mercy1