- Maximian, Emperor of Rome, approximately 240-3101
- Medea, consort of Aegeus, King of Athens (Mythological character)1
- Medici, Alamanno de'1
- Medici, Bernardo de'1
- Medici, Niccolò de'1
- Medicine, Magic, mystic, and spagiric1
- Mediterranean Sea--Adriatic Sea1
- Middle Ages1
- Middle East--Jerusalem1
- Middle East--Palestine1
- Missouri--Saint Louis1
- Monastic and religious life of women1
- Monasticism and religious orders--Rules1
- Monochord1
- Monte di pietà (Florence, Italy)1
- Morale1
- Morso family1
- Mugiello (Italy)1
- Music1
- Music theory1