| Your Precious Pet's Names |
| Oberon | Odelia | |||||
| Odette | Odie | Odin | Oedipus | Officer | Oghris | Oki |
| Olive | Oliver | Olivia | Olympia | Oma | Omar | Onslow |
| Ooyelia | Opal | Ophelia | Opium | Oprah | Opus | Orange |
| Oriana | Orino | Oriole | Orion | Orlando | Oro | Orson |
| Orwell | Osbert | Oscar | Oso | Othello | Otis | Otto |
| Ouzel | Ouzo | Owen | Ozzy | |||