| Name | Meaning | Gender | Origin |
|---|
| Lynx | | Male | |
| Macavity | | Unisex | |
| Mango | after the character in Saturday Night Live | Unisex | |
| Marvin | beautiful sea; good friend | Male | Welsh |
| Max | Large spring | Male | English |
| Max | Large spring | Male | English |
| Maximus | greatest | Male | Latin |
| Maxwell | Capable
| Male | Scottish |
| Meggie | Pearl | Unisex | English |
| Mel | Scottish, settlement on infertile land | Male | English |
| Merlin | Character on Chocolate Frog card.
| Male | Welsh |
| Mewy | | Unisex | |
| Milo | Merciful.
| Male | Latinized |
| Milo | Merciful.
| Male | Latinized |
| Minka | Strong | Male | German |
| Mino | French for Puss | Unisex | |
| Minou | | Unisex | |
| Minouche | | Unisex | Hebrew |
| Minx | | Unisex | |
| Misha | Variant of Michael.
| Male | Russian |
| Mojo | Good luck charm. | Unisex | |
| Moose | Largest member of the deer family. Moose have heavy brown bodies with humped shoulders and broad antlers. | Unisex | |
| Muffy | | Unisex | |
| Nathan | given | Male | Hebrew |
| Neo | from The Matrix movies | Male | Latin |