| Name | Meaning | Gender | Origin |
|---|
| Midnight | Intense darkness, the middle of the night | Male | English |
| Milkshake | | Male | |
| Milky | | Female | |
| Milo | Merciful.
| Male | Latinized |
| Milo | Merciful.
| Male | Latinized |
| Mini Me | | Unisex | Hebrew |
| Mischief | One that causes minor trouble or disturbances | Male | |
| Missy | Informal term for young woman | Female | English |
| Misty | misty.
| Female | English |
| Misty | misty.
| Female | English |
| Mittens | | Unisex | |
| Mojo | Good luck charm. | Unisex | |
| Mole | | Unisex | Hebrew |
| Molly | Bitter
| Female | English |
| Monkey | | Unisex | |
| Monty | From Montgomer - The mountain hunter. | Male | English |
| Moo | | Unisex | |
| Moo | | Unisex | |
| Moose | Largest member of the deer family. Moose have heavy brown bodies with humped shoulders and broad antlers. | Unisex | |
| Mouse | A small rodent with a long tail and small rounded ears. | Unisex | |
| Mouser | | Unisex | |
| Mousetrap | | Unisex | |
| Ms. Kitty | | Unisex | Hebrew |
| Muffin | A small cup shaped cake | Unisex | |
| Muppet | | Unisex | Hebrew |