| Name | Meaning | Gender | Origin |
|---|
| Mustard | Seeds ground into paste and used as a spicy condiment | Unisex | |
| Mya | Mine | Female | Latin |
| Nacho | Small triangles of tortilla topped with cheese. | Male | Word |
| Nana | A grandmother. | Female | English |
| Neela | sapphire blue | Female | Hindi |
| Nelia | horn | Female | Latin |
| Nigel | Black haired one. | Male | Irish |
| Noir | | Unisex | |
| Nola | Noble or Famous | Female | Gaelic |
| Nugget | as in Chicken | Unisex | |
| Nutmeg | | Male | |
| Odette | happy home | Female | |
| Oklahoma | | Male | Hebrew |
| Oleander | | Unisex | |
| Olive | kind one; olive tree, peace. Symbol of peace. A small oval fruit. | Female | English |
| Olivia | Olive
| Female | Latin |
| Ollie | Latin, olive tree | Male | English |
| Onyx | A gemstone with bands of different colours. | Male | |
| Opal | Australian gemstone of remarkable colours, usually red, blue or green | Female | Sanskrit |
| Opal | Australian gemstone of remarkable colours, usually red, blue or green | Female | Sanskrit |
| Orange | Round citrus fruit originating in Southeast Asia. | Female | Fruit |
| Orange | Round citrus fruit originating in Southeast Asia. | Female | Fruit |
| Orchid | | Female | |
| Oreo | American cookie brand consisting of two chocolate wafers with white cream filling. | Male | |
| Oreo | American cookie brand consisting of two chocolate wafers with white cream filling. | Male | |