- Midland, Cabarrus County, North Carolina, United States1
- Midlands4
- Milos, Nisos, Cyclade Islands, Aegean Islands, Greece1
- Mississippi River1
- Missouri, United States2
- Montclair, Essex County, New Jersey, United States1
- Monte Baldo, Verona, Italy2
- Monte Rose, Liguria, Italy1
- Morris County, New Jersey, United States2
- Mount Holyoke, Hampshire County, Massachusetts, United States1
- Mount Vesuvius, Napoli province, Campania, Italy1
- Mount Vesuvius, Napoli, Campania, Italy6
- Mt. Etna, Sicily, Italy1
- Muscaonge (Muskallonge) Lake, Oxbow, Theresa Township, Jefferson County, New York, United States3
- Nashville, Davidson County, Tennessee, United States1
- Neidermennig, Rheinland, Germany1
- Neshaminy Creek, Philadelphia County, Pennsylvania, United States1
- New Almaden District, Santa Cruz Mountains, Santa Clara County, California, United States1
- New Hampshire, United States3
- New Jersey, United States1