| Name | Meaning | Gender | Origin |
|---|
| Rufus | Red | Male | Latin |
| Rusty | Rusty, full of rust | Unisex | American English |
| Ryder | One who rides | Unisex | English |
| Sabre | | Unisex | Hebrew |
| Sage | Aromatic herb | Unisex | English |
| 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 |
| Sebastian | Man from Sebaste | Male | Latin |
| Sedona | | Unisex | Hebrew |
| Seraphim | An Angel Like Being Of A Lower Order | Male | English |
| Seth | Appointed | Male | Hebrew |
| Shadow | Shadow | Unisex | English |
| Silver | Silver (the metal or colour) | Male | English |
| Slate | | Unisex | Hebrew |
| Smoky | | Unisex | Hebrew |
| Soda | A carbonated water. | Unisex | English |
| Sonic | Approaching the speed of sound, fast-paced | Unisex | English |
| Sparky | Animated, lively. | Unisex | English |
| Speedy | Rapid motion, swift. | Unisex | English |
| Spencer | Someone who gives out goods | Male | French |
| Spider | An eight legged insect | Unisex | English |
| Spike | A long, thick sharp-pointed piece of wood or metal | Male | English |
| Spud | Slang for potato. | Unisex | English |
| Spunky | Spirited, plucky. | Unisex | English |
| Stretch | To extend to full length. | Unisex | English |