| Name | Meaning | Gender | Origin |
|---|
| Rosie | Rose | Female | Latin |
| Roxy | Star | Female | Persian |
| Rusty | Rusty, full of rust | Unisex | American English |
| Sadie | Princess | Female | Hebrew |
| Samantha | Listener | Female | Aramaic |
| Sammy | His name is God | Unisex | Hebrew |
| Sarge | Noncommissioned Army or Air Force rank | Unisex | English |
| Sasha | Defending men | Unisex | Greek |
| Sasquatch | Has extra toes and hence is a bigfoot | Unisex | English |
| Sassy | Lively and spirited | Unisex | English |
| Saturn | Sixth and second largest planet away from the Sun. | Unisex | English |
| Scar | From The Lion King | Unisex | English |
| Shadow | Shadow | Unisex | English |
| Shark | | Unisex | Hebrew |
| Sheba | Daughter of an oath | Female | Hebrew |
| Shelby | A place where willows grow | Female | American English |
| Shorty | Of less than average size | Unisex | English |
| Sierra | Mountain range | Female | Spanish |
| Silvia | Wooded | Female | Latin |
| Simba | Lion | Female | Swahili |
| Skittles | | Unisex | Hebrew |
| Sky | Sky | Unisex | Norse |
| Slim | Slender in proportion to height. | Unisex | English |
| Sophia | Wisdom | Female | Greek |
| Sophie | Wisdom | Female | Greek |
| Sparky | Animated, lively. | Unisex | English |
| Speedy | Rapid motion, swift. | Unisex | English |
| Squeaky | | Unisex | Hebrew |
| Squirt | Slang for a small person | Unisex | English |
| Stumpy | A short, thickset person | Unisex | English |