| Name | Meaning | Gender | Origin |
|---|
| Mannix | Little monk | Male | Gaelic |
| Marmaduke | Devotee of Maedoc | Male | Gaelic |
| Marvin | Uncertain, possibly eminent marrow | Male | Welsh |
| Maurice | Moor | Male | Latin |
| Max | Little Maximus | Male | Latin |
| Maxi | Pet form of names starting with Max | Unisex | English |
| Mel | Uncertain, possibly bad town | Unisex | English |
| Melvin | Uncertain, possibly bad town | Male | English |
| Mercy | Compassion | Female | English |
| Michaelangelo | | Unisex | Hebrew |
| Mickey | Who is like God? | Unisex | Hebrew |
| Mikey | Who is like God? | Unisex | Hebrew |
| Minnie | Will, desire + helmet, protection | Female | Germanic |
| Missy | Bee | Female | Greek |
| Mister | | Unisex | Hebrew |
| Misty | Misty | Female | English |
| Molly | Uncertain, maybe bitter | Female | Hebrew |
| 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 |
| Morey | Dark Skinned | Unisex | Latin |
| Morris | Moor | Male | Latin |
| Moses | Drawn out of the water | Male | Hebrew |
| Mufasa | From The Lion King | Unisex | English |
| Nikki | Victory of the people | Female | Greek |
| Ninja | | Unisex | Hebrew |
| Oberon | Noble bear | Unisex | German |
| Oscar | Divine spear | Male | English |
| Penny | Weaver | Female | Greek |
| Pepper | Pepper | Female | English |
| Phoebe | Bright | Female | Greek |