- Martini, Luca, 1980-1
- Martyrologies1
- Martyrs1
- Marucelli, Benedetto1
- Marucelli, Francesco, 1625-17031
- Mary Magdalene, Saint1
- Mary, Queen of Scots, 1542-15871
- Masorah1
- Mass--Celebration1
- Massacre of the Holy Innocents in art1
- Mathematical recreations1
- Mathematics, Greek1
- Mathematics, Jewish1
- Maximus, of Turin, Saint, active 4th century-5th century1
- Maʻariv1
- Meat inspection (Jewish law)1
- Medea, consort of Aegeus, King of Athens (Mythological character)1
- Medici, Alessandro de', 1510-15371
- Medici, Andrea de'1
- Medici, Carlo de'1