| Name | Meaning | Gender | Origin |
|---|
| Matilda | Powerful battler | Female | Germanic |
| Matilde | Powerful battler | Female | German |
| Mattie | Powerful battler | Female | German |
| Matty | Gift of God | Unisex | Hebrew |
| Maud | Powerful battler | Female | German |
| Maude | Powerful battler | Female | German |
| Melvin | Uncertain, possibly bad town | Male | English |
| Millard | Guardian of the mill | Male | English |
| Morgan | Uncertain, perhaps bright sea | Female | Welsh |
| Murdock | Sea | Male | Gaelic |
| Murphy | Sea warrior | Male | Gaelic |
| Murray | Man of the sea | Male | Gaelic |
| Neala | Ruler | Female | Gaelic |
| Ned | Wealth protector | Unisex | English |
| Neda | Born on sunday | Female | Slovak |
| Neil | Champion | Male | Gaelic |
| Nero | Stern | Male | Latin |
| Nolan | Chariot-fighter, champion | Male | Gaelic |
| Noland | Chariot-fighter, champion | Unisex | Gaelic |
| Olesia | Helper And Defender Of Mankind | Female | Polish |
| Oli | Olive Tree | Unisex | English |
| Olier | | Male | Hebrew |
| Oliver | Elf army | Male | French |
| Olivia | Elf army | Female | English |
| Ollie | Elf army | Male | French |
| Ondrea | Like a woman | Female | Czech |
| Orman | Forest | Male | Turkish |
| Ormond | Bears mountain | Unisex | English |
| Oscar | Divine spear | Male | English |
| Ouida | Fame and war | Female | Germanic |