| Name | Meaning | Gender | Origin |
|---|
| Mike | Hebrew, who is like God? | Male | English |
| Milo | Merciful.
| Male | Latinized |
| Milo | Merciful.
| Male | Latinized |
| Minnie | Form of Williamina
| Female | English |
| Minnie Mouse | | Unisex | |
| Mirage | | Male | |
| Mo | bitter | Female | English |
| Molly | Bitter
| Female | English |
| Mowgli | | Male | |
| Mufasa | from The Lion King | Unisex | |
| Myrtle | a flower, symbol of victory | Female | Greek |
| Nala | African for love, after the character in the Lion King movies | Female | African |
| Nani | Hawaiin for beautiful | Unisex | |
| Nanny | Grace | Unisex | Hebrew |
| Napoleon | Hound Dog from the AristoCats
| Male | Greek |
| Nemo | from the glen | Male | Greek |
| Nessus | character in sf novel by Larry Niven, Ringworld | Unisex | |
| Nigel | Black haired one. | Male | Irish |
| Octavius | eighth | Male | Latin |
| Oddball | | Unisex | |
| Odie | Melody | Unisex | French |
| Oliver | The olive tree. The biblical olive tree symbolizes fruitfulness and beauty and dignity. Extending an olive branch signifies an offer of peace.
| Male | Latin |
| Olivia | Olive
| Female | Latin |
| Orville | Gold town.
| Male | |
| Otto | Born eighth or wealthy
| Male | |