| Modred | | - | Welsh Mythology, Arthurian Romance | |
| Monica | | MAHN-i-kə (English) | English, Italian, Portuguese, Romanian, Late Roman | |
| Mordred | | - | Welsh Mythology, Arthurian Romance | |
| Morgaine | | - | Arthurian Romance | |
| Morgan (2) | | - | Arthurian Romance | |
| Morgen | | - | Arthurian Romance | |
| Naenia | | - | Roman Mythology | |
| Naevius | | - | Ancient Roman | |
| Narcisa | | - | Portuguese, Spanish, Italian, Romanian | |
| Narcissa | | nar-SIS-ə (English) | Late Roman | |
| Narcissus | | nar-SIS-əs (English) | Greek Mythology (Latinized), Late Roman, Biblical | |
| Natalia | | nah-TAH-lyah (Polish, Italian, Spanish) | Polish, Italian, Spanish, Romanian, Georgian, Late Roman | |
| Natalius | | - | Late Roman | |
| Nazarenus | | - | Late Roman | |
| Nazarius | | - | Late Roman | |