| Name | Meaning | Gender | Origin |
| Sabre | | Unisex | Hebrew |
| Sadie | Princess | Female | Hebrew |
| Sammy | His name is God | Unisex | Hebrew |
| Samson | Sun | Male | Hebrew |
| Sandy | Defending men | Male | Greek |
| Sasha | Defending men | Unisex | Greek |
| Sasquatch | Has extra toes and hence is a bigfoot | Unisex | English |
| Sassy | Lively and spirited | Unisex | English |
| Satan | The Devil and adversary of God | Unisex | English |
| Satin | Amber | Female | Armenian |
| Saturn | Sixth and second largest planet away from the Sun. | Unisex | English |
| Scarlet | Scarlet | Female | English |
| Scooby | | Unisex | Hebrew |
| Scooter | One who goes suddenly and speedily. | Unisex | English |
| Shark | | Unisex | Hebrew |
| Sheba | Daughter of an oath | Female | Hebrew |
| Shelby | A place where willows grow | Female | American English |
| Sherlock | With cropped hair | Male | English |
| Sierra | Mountain range | Female | Spanish |
| Snuffles | | Unisex | Hebrew |
| Sophie | Wisdom | Female | Greek |
| Spencer | Someone who gives out goods | Male | French |
| Stretch | To extend to full length. | Unisex | English |
| Suede | Swedish | Unisex | English |
| Sugar | A sweet powder from sugar cane. Slang for sweetheart. | Female | English |
| Talon | A claw | Male | English |
| Tank | A large metal container. A heavily armed combat vehicle | Unisex | English |
| Tasha | (Christ's) birthday | Female | Latin |
| Tempest | Storm | Female | English |
| Tex | Of Texas | Unisex | English |