| Name | Meaning | Gender | Origin |
|---|
| Roxy | Star | Female | Persian |
| Ruby | Red | Female | Latin |
| Rudy | Famous wolf | Male | Germanic |
| Rufus | Red | Male | Latin |
| Rugrat | | Unisex | Hebrew |
| Rusty | Rusty, full of rust | Unisex | American English |
| Sabre | | Unisex | Hebrew |
| Sadie | Princess | Female | Hebrew |
| Sam | He is called god | Male | Hebrew |
| Sammy | His name is God | Unisex | Hebrew |
| Samson | Sun | Male | Hebrew |
| Sandy | Defending men | Male | Greek |
| Sasha | Defending men | Unisex | Greek |
| Sassy | Lively and spirited | Unisex | English |
| Scout | Observer | Unisex | American English |
| Scruff | | Unisex | Hebrew |
| Shadow | Shadow | Unisex | English |
| Sheba | Daughter of an oath | Female | Hebrew |
| Sherlock | With cropped hair | Male | English |
| Sigmund | Protector | Male | German |
| Smoky | | Unisex | Hebrew |
| Sonic | Approaching the speed of sound, fast-paced | Unisex | English |
| Sophie | Wisdom | Female | Greek |
| Sparky | Animated, lively. | Unisex | English |
| Spice | Plant used to flavour food or beverages. | Unisex | English |
| Spike | A long, thick sharp-pointed piece of wood or metal | Male | English |
| Spring | To burst forth | Female | English |
| Sugar | A sweet powder from sugar cane. Slang for sweetheart. | Female | English |
| Sundance | | Unisex | Hebrew |
| Suzy | Lily | Female | Hebrew |