| Name | Meaning | Gender | Origin |
|---|
| Marvin | Lives By The Sea | Male | Celtic |
| Marvina | Renowned Friend. Feminine Of Marvin Lives By The Sea. | Female | Celtic |
| Meredith | Protector Of The Sea | Female | Celtic |
| Merial | Sea-Bright | Female | English |
| Meriel | Variant Of Muriel Shining Sea. | Female | English |
| Merric | Ruler Of The Sea | Male | Celtic |
| Merrick | Strong Ruler. Ruler Of Sea | Male | English |
| Merril | Shining Sea. | Male | English |
| Merrill | Shining Sea. | Male | English |
| Morgan | Fighter Of The Sea | Male | Irish |
| Morgance | Dweller Of The Sea | Female | Celtic |
| Morgane | Dweller Of The Sea | Female | Celtic |
| Morgayne | Medieval Form Of Welsh Morcan Meaning Bright Sea. | Female | Irish |
| Moriarty | Expert Seaman | Male | Irish |
| Morogh | Man Of The Sea | Male | Scottish |
| Morrissey | Choice Of The Sea | Male | Irish |
| Morven | Lives By The Sea | Male | Celtic |
| Morvyn | Lives By The Sea | Male | Celtic |
| Moryn | Lives By The Sea | Male | Celtic |
| Mufidy | Man Of The Sea | Male | Scottish |
| Muiel | Knows The Sea | Female | Irish |
| Muircheartaigh | Expert Seaman | Male | Irish |
| Muireadhach | Lord Of The Sea | Male | Irish |
| Muirfinn | Dweils Near The Beautiful Sea | Male | Scottish |
| Muirgheal | Knows The Sea | Female | Irish |
| Murchadh | Protector Of The Sea | Male | Gaelic |
| Murdoc | Seaman | Male | Celtic |
| Murdoch | Seaman | Male | Celtic |
| Murdock | Protector Of The Sea | Male | Scottish |
| Murel | Knows The Sea | Female | Irish |