| Name | Meaning | Gender | Origin |
|---|
| Mako | Child of truth | Unisex | Japanese |
| Maui | God of fire | Unisex | Hawaiian |
| Maverick | Dissenter | Unisex | English |
| Maxi | Pet form of names starting with Max | Unisex | English |
| Mickey | Who is like God? | Unisex | Hebrew |
| Midnight | Intense darkness, the middle of the night | Unisex | English |
| Mighty | | Unisex | Hebrew |
| Moose | Largest member of the deer family. Moose have heavy brown bodies with humped shoulders and broad antlers. | Unisex | English |
| Mozart | | Unisex | Hebrew |
| Ninja | | Unisex | Hebrew |
| Nugget | As in Chicken | Unisex | English |
| Pax | Peace | Unisex | Latin |
| Pluto | Wealth, riches | Unisex | Greek |
| Pollux | Coronet | Unisex | Greek |
| Rainbow | Rainbow | Unisex | English |
| Rambo | | Unisex | Hebrew |
| Rebel | One that resists of defies authority | Unisex | English |
| River | River | Unisex | English |
| Rogue | | Unisex | Hebrew |
| Roman | Roman | Unisex | Latin |
| Rusty | Rusty, full of rust | Unisex | American English |
| Sable | Sable (black) | Unisex | English |
| Sabre | | Unisex | Hebrew |
| Sammy | His name is God | Unisex | Hebrew |
| Sampson | Sun | Unisex | Hebrew |
| Sarge | Noncommissioned Army or Air Force rank | Unisex | English |
| Sasha | Defending men | Unisex | Greek |
| Sasquatch | Has extra toes and hence is a bigfoot | Unisex | English |
| Sassy | Lively and spirited | Unisex | English |
| Saturn | Sixth and second largest planet away from the Sun. | Unisex | English |