- Manuscripts, English1
- Manuscripts, European1
- Manuscripts, Greek1
- Manuscripts, Greek (Medieval and modern)1
- Manuscripts, Nahuatl1
- Manuscripts, Persian1
- Manuscripts, Spanish1
- Manuscripts, Syriac1
- Martinus, Polonus, -12791
- Martyrs1
- Mary Magdalene, Saint1
- Massachusetts--Wellesley1
- Massachusetts--Williamstown1
- Maximus, of Turin, Saint, active 4th century-5th century1
- Medea, consort of Aegeus, King of Athens (Mythological character)1
- Medicine, Medieval1
- Medicine--Formulae, receipts, prescriptions1
- Mexico--Chiapas1
- Michael (Archangel)1
- Michigan--Kalamazoo1