| Name | Meaning | Gender | Origin |
|---|
| Lobo | Wolf | Male | Spanish |
| Logan | Hollow | Unisex | Gaelic |
| Louie | Fame and war | Male | Germanic |
| Lucky | Fortunate | Unisex | English |
| Luke | Man from Lucania | Male | Greek |
| Mac | Son of | Male | Gaelic |
| Madison | Son of Maud | Unisex | English |
| Magic | Possessing qualities that produce baffling effects | Unisex | English |
| Major | Greater | Male | Latin |
| Malcolm | Columba's servant | Male | Gaelic |
| March | Boundary | Unisex | French |
| Marley | Pleasant wood | Female | English |
| Marmaduke | Devotee of Maedoc | Male | Gaelic |
| Marty | From the god Mars | Male | Latin |
| Max | Little Maximus | Male | Latin |
| Maximus | The greatest | Male | Latin |
| Maxwell | Maccus's stream | Male | English |
| Melvin | Uncertain, possibly bad town | Male | English |
| Merlin | Sea fort | Male | Welsh |
| Merv | Famous | Male | English |
| Mick | Who is like God? | Male | Hebrew |
| Mickey | Who is like God? | Unisex | Hebrew |
| Mighty | | Unisex | Hebrew |
| Miles | Uncertain, perhaps peaceful | Male | Germanic |
| Milo | Uncertain, perhaps peaceful | Male | Germanic |
| Mister | | Unisex | Hebrew |
| Misty | Misty | Female | English |
| Mo | Moor | Unisex | Latin |
| Monty | Gomeric's hill | Male | French |
| Moose | Largest member of the deer family. Moose have heavy brown bodies with humped shoulders and broad antlers. | Unisex | English |