| Name | Meaning | Gender | Origin |
|---|
| Puddles | | Unisex | Hebrew |
| Puff | Expelling breath, a gust of wind or a small amount of smoke. | Unisex | English |
| Pug | Short for pugnacious; combative, belligerent. A breed of dog originating in China. | Unisex | English |
| Puppy | | Unisex | Hebrew |
| Purty | | Unisex | Hebrew |
| Queen | Female ruler | Unisex | English |
| Rags | | Unisex | Hebrew |
| Rainy | To Regin Over Others | Unisex | User Contributed |
| Red | Red | Unisex | English |
| Reggie | Ruler with counsel | Unisex | Germanic |
| Reno | Ruler with counsel | Unisex | Germanic |
| Riff | | Unisex | Hebrew |
| Rin | Cold | Unisex | Japanese |
| Rocket | To move swiftly and powerfully | Unisex | English |
| Rorschach | | Unisex | Hebrew |
| Runt | | Unisex | Hebrew |
| Rusty | Rusty, full of rust | Unisex | American English |
| Sammy | His name is God | Unisex | Hebrew |
| Sampson | Sun | Unisex | Hebrew |
| Santa | Saintlike | Unisex | Spanish |
| Satan | The Devil and adversary of God | Unisex | English |
| Scamp | A mischievous youngster | Unisex | English |
| Scamper | | Unisex | Hebrew |
| Scout | Observer | Unisex | American English |
| Scuttle | | Unisex | Hebrew |
| Sea | Mercy in god | Unisex | Hebrew |
| Seymore | Our cat who likes to hide that we want to see more of | Unisex | English |
| Shadow | Shadow | Unisex | English |
| Shaggy | Bushy and matted (hair), unkempt. | Unisex | English |
| Shelly | Clearing near a ledge | Unisex | English |